What additions should I add to my rig?

[Statik]

Hey guys, so I'm getting to the point where I want to start adding some more goodies to my rig, but at this point, I'm really not sure what to add. My build is as follows:

Mobo: Gigabyte UD3 990FX

CPU: AMD FX-8320 @ 4.2GHz

RAM: 8GB G.SKILL 1333MHz

Video Card: x1 Evga GTX 770

Case: Zalman Z11

Cooling: Corsair H80i w/ x2 Noctua NF-F12

Hard Drives: x1 Samsung Evo 250gb | x1 Seagate 1TB HDD

A few things I'm looking into is getting some LED lights, and placing them around the windows and the front on my case. My 770 doesn't light up on the side, and with only a LED fan at the front and top it's extremely dark. Does anyone have any personal preferences to good LED lighting strips to use?

I was also considering swapping out the two stock 120mm fans with Notctua's, just for silence and a bit more performance.

But from there I'm not really sure on what I should add. I've been contemplating on purchasing a sound card (Asus Xonar Essence STX to be exact), and from there branching off to a dedicated mic (Snowball, blue yeti, etc), with a dedicated headphones, instead of my current headset (Sharkoon X-Tactic S7).

Also I currently only have 1 monitor (27" Asus VE276), and am considering getting a second. Which would be a more worthy investment?

Also if you have any other idea's for additions or possibly mods, I'd be happy to hear them!

Thanks,

EDIT: I'm also not a huge fan of my case, so I'm actually somewhat toying with the idea of buying a new one, nit I'm not sure if i want to wait, or get a new one ASAP