Lauen

well, if they're on discount, they're an alright buy. I've had three pairs of those, before I knew better, but I still hold my thoughts, that these are better than the majority of gaming headsets, when it comes to how they sound. they are also ridiculously comfortable. they don't leak much, but there are headphones that leak less, just saying. but overall, I'd say they're alright. but if you have the dough for it- closed headphones (Beyerdynamic DT770 32ohm if you can) with something like a zalman clip on mic will be better.

Better to get a Pebble watch for media controls.

well, if they're on discount, they're an alright buy. I've had three pairs of those, before I knew better, but I still hold my thoughts, that these are better than the majority of gaming headsets, when it comes to how they sound. they are also ridiculously comfortable. they don't leak much, but there are headphones that leak less, just saying. but overall, I'd say they're alright. but if you have the dough for it- closed headphones (Beyerdynamic DT770 32ohm if you can) with something like a zalman clip on mic will be better.

Lol at all the people saying get separate headphones and mic. I know that's what we usually recommend around here, but the PC360 is, like, the one exception.

[RANT]
 
Don't bother getting a soundcard unless the onboard is broken somehow and you don't want external stuff, and whatever you've heard, the Phoebus isn't gaming optimized. in fact, from what I've heard (sort of experienced) it's worse having it compared to just onboard. reasons:
 
A lot of people have issues with the mic circuits on it, it gets interference from the graphics card, resulting in noises going through the mic. example: you're playing, say Minecraft, and talking to friends on skype. They will hear a high pitched noise, which is directly conncted to how many FPS you have, the higher FPS, the higher pitch noise. As far as I know, RMA-ing doesn't help unless you get a new card that magically doesn't have this interference. 
 
It's overpriced. by a lot. it's not really worth half of it, to be honest. The only noticeable difference in sound from onboard is how loud it can get, due to it being capable of pushing 600 ohm headphones. 
 
If you're getting it because they claim better positional audio, that's bullshit. They have virtual surround, powered by Dolby. if you want virtual surround, installing Razer Surround will do exactly what you want it to do, for free. or you could just leave it to the game itself, which would be the simplest and best way of doing it. 
 
 
Now, you might see in my sig, that I have a soundcard in my rig. This is from before I even knew that there existed such as my M50s and the Fiio E10 (which I don't own because it's over double the price here in Norway, ruining the price/"performance" ratio), and the reason I got is becasue my old DX had the same microphone issues as the Phoebus, and they have the same audio processor, if I remember correctly. 

Now I want a bowl of cereal. 

Then you would need an amp, the conglomerate recommends FiiO E10's

No real point in buying one. The amp will do nothing more but make it louder (which it already is) and add some coloration, which he can just do with EQ.
 
I don't really see a point in a ODAC with only 558, so the E10 is really the only worthy option. Even then I don't think it would matter that much to bother. 

350 SE are closed design so they're out
 
Out of the 360 and 363d I'd go 360. It's cheaper and you're not paying for the extra virtual 7.1 sound card with the 363d. You can use the option @ShearMe posted.
 
http://linustechtips.com/main/topic/5991-sennheiser-pc-363d-vs-pc-360/
 
They also use the same drivers as the HD558/598 so if you don't need a mic or want to look at getting a cheaper headphone + mic combo, then that's another option you can take.

I wouldn't say the 558's ruin metal. I've used the Sennheiser PC360 for some time (basically the same as 558's) and I thoroughly enjoyed every moment of it. Now I'm using some M50s most of the time, and for general metal, these just sound better overall, not by all that much though, mostly the bass, but these M50s really shine with progressive metal and symphonic metal. 

I wouldn't say the 558's ruin metal. I've used the Sennheiser PC360 for some time (basically the same as 558's) and I thoroughly enjoyed every moment of it. Now I'm using some M50s most of the time, and for general metal, these just sound better overall, not by all that much though, mostly the bass, but these M50s really shine with progressive metal and symphonic metal. 

Thanks for the adivce. I will save the money for other upgrades!

You are not in need of any form of soundcard, in my opinion. There is little to no difference going from my rig at home (Xonar D2X soundcard) to the laptop at work (Realtek of some sort). The difference is just how loud it can get.
 
The PX360's don't really need amplification, as (I think) it's 50 Ohms or something, which should work fine with any integrated audio. The only thing you'd really get anything good out of, is getting something like the Fiio E10, if you're dead set on upgrading. I see no need to get any new things, unless there is something wrong with your current setup, like buzzing or crackling. 

Getting any amp won't really hurt but keep in mind unless you just have dollar bills to throw around it will be a waste to a certain degree

Amplifiers simply amplify the signal put into them. Most have a volume dial. DACs transform digital information into analog signals. The FiiO E10 is a USB DAC and Amplifier in one nice tiny package, suitable for most headphones.
 
However, I personally doubt you really need anything, especially if you just got a new motherboard. The PC 360 uses the same drivers as the HD 558, and they are not hard to drive.

You are not in need of any form of soundcard, in my opinion. There is little to no difference going from my rig at home (Xonar D2X soundcard) to the laptop at work (Realtek of some sort). The difference is just how loud it can get.
 
The PX360's don't really need amplification, as (I think) it's 50 Ohms or something, which should work fine with any integrated audio. The only thing you'd really get anything good out of, is getting something like the Fiio E10, if you're dead set on upgrading. I see no need to get any new things, unless there is something wrong with your current setup, like buzzing or crackling. 

If I do get one of these audio solutions it wouldn't matter what they would look like since I would not take them out in public. Still can't decide on which to get, I guess I'll probably get the cheapest when it gets close to Black Friday / Cyber Monday.

Those look very nice. They say it's compatible with "smartphones", I'm gonna send them an email to ask if it is compatible! 

got a little sidetracked, lol 

If you plan to use a DT series with your phone, you'd be better off just getting a Custom One Pro - less bulky cable, 16 ohms, usually cheaper than the 32 ohm DT versions, bass adjustment, etc etc etc.

The only thing I don't like about the mics on Sennheiser's headsets is that they are soooo big and bulky. It makes them more difficult to reposition than some other solutions..
 
They do sound great though.

Voting for the PC360, as is sounds pretty much the same as the 558's, and the mic on it is pretty damn good, and it's nice to have the mic on the headset, instead of a standalone one. that's just my opinion though. 
 
it could be nice having the snowball and 558's, that way you can use the 558's in public, and you won't have an antenna-looking thingy on the side of the headset, making you look like some sort of robot or something, lol. 
 
take whatever's cheapest for you. I know here in norway, the PC360's are cheaper by about 40 bucks. 

^ pretty good explanation. 
 
but if you're only using the vulcans, I see no reason in buying a soundcard, at all. unless your current sound has issues, no use in getting anything. and for positional audio: I've tried virtual surround, and I've had better positional sound in all games without silly virtual. I've been using Siberia v2's and Sennheiser PC360 for my games, haven't played anything with my M50s, but it's all down to the game if you get alright positional audio. CS, for example, if you have the audio set to headphones in the game, I can't think of anything better than that. 

^ pretty good explanation. 
 
but if you're only using the vulcans, I see no reason in buying a soundcard, at all. unless your current sound has issues, no use in getting anything. and for positional audio: I've tried virtual surround, and I've had better positional sound in all games without silly virtual. I've been using Siberia v2's and Sennheiser PC360 for my games, haven't played anything with my M50s, but it's all down to the game if you get alright positional audio. CS, for example, if you have the audio set to headphones in the game, I can't think of anything better than that. 

http://www.amazon.com/Pioneer-SE-A1000-Over-Ear-Stereo-Headphones/dp/B0033PROOY/ref=sr_1_53?s=aht&ie=UTF8&qid=1384889454&sr=1-53
 
found a sweet deal on these. for US though, so if you're somewhere else, no use. 
 
EDIT: this actually makes me wish I lived in the US right now.