k_benlevi

It resembles windows a bit, depends on your definition of user friendly. 

I believe CentOS 6 is the only distro with a stable enough 32 bit implementation. I have had lots of issues with other popular distros.

I think 44 pin is regular CF, and 50 pin is for CF hard drives that need more power (probably +5V or something)

I only came across 44-pin IDE drives. No 50-pin...  
Maybe try eBay?

experienced with asus xonar and creative sound blaster z:
- the xonar had absolutely no power to drive headphones beyond 40ohm, the driver was a solid 2/10(no joke)
- the creative is superior in every chapter, can properly drive more power hungry headsets or headphones, driver is a solid 7/10.
The new cards from asus have the same specs as the creatives now tho, the strix soar is priced almost the same as the creative sound blaster z. So it depends what driver you like the most.
If you own the logitech z906 you can use an optical cable and turn on the DTS encoder on the creative sound blaster z, I find it sounds way better on DTS rather than on analogue cables. The asus card has to have something similar to DTS, so you might be able to use it with an optical cable too.

That sound card is aged old, and the on board sound sound could probably match the sound quality. For superior sound, you can upgrade it to a nice ASUS Xonar series sound card (of course, you know the drill, the low end model is mostly no better sound just better amp and filtering for a clean static free sound, and once you pass the about 100$ mark you have better sound)
 
HOWEVER, the field of sound card has changed over the years. Now you, thanks to competition and  growing demand in music production by people doing this as a hobby, professionals, and various creators, and so on, external sound card powered by USB, called a DAC (Digital Analogue Converter) (which includes an Amp, and everything else to make an external sound card, basically), are a better, allowing you to get a better for your money. Something to look into.
 
Now, I am not experts, and the fine member of this community can definitely be able to help you. Sadly, you posted in the wrong forum section, posting in the right place will get you the best advice and help. I moved your thread to Audio section.
 

a pci card will be slow, cheap cards like to fail and take data at times. Raid 5 on cards will be slow, but just use storage spaces.

this? http://www.ebay.com/itm/PCI-to-4-ports-SATA-Serial-ATA-RAID-Sil3114-3114-Converter-Controller-I-O-Card-/161225040708?hash=item2589c2e344:g:41EAAOSwDNdVi8C2

eBay should be full of them.
 
For something easier to use, DealExtreme can help you out (just keep in mind they ship from Asia so it could take weeks for stuff to arrive to you)
 
Examples:
18$  4 port silicon image sil3114 + 2 sata cables : http://www.dx.com/p/silicon-image-4-port-sata-pci-expansion-card-4660#.WSx7n24lFhE
11.79$ 4 sata silicon image chipset sil3114 : http://www.dx.com/p/upgrade-pci-to-sata-4-port-3114-raid-card-414550#.WSx4Lm4lFhE
12.34$  4 sata silicon image chipset , 4 sata + 2 sata cables : http://www.dx.com/p/iocrest-mm-sa3114-4i-sil3114-4-port-sata-pci-expansion-card-w-two-sata-cables-black-268674#.WSx4U24lFhE
11.36$ via chipset 2sata + ide  : http://www.dx.com/p/sata-ide-ports-pci-controller-raid-card-adapter-106963#.WSx4Z24lFhE
 
Note that most if not all of these are SATA 1 or SATA 2 (max 150 MB/s) and some may not have drivers for 64 bit windows , or windows versions higher than windows 7
You can simply look at the pictures of the cards or description and then google after the code of the chip used plus driver for example "via vt6421a driver windows 7" to make sure the card would work for you.
Some new high capacity hard drives may not work with cards that can only work at 150 MB/s due to lack of support for some features that are only present with newer SATA2 or SATA3.
 
I think silicon image chips are better (more reliable and better drivers) IF you have drivers for your operating system and if you the hard drives are fine with talking on the sata 1 (150 MB/s) .. and i suppose if you need a pci card it would be for an older system and you're probably going to use older hard drives which would work just fine.
 
 
Also, keep in mind that the whole PCI interface is capable of maximum 133 MB/s so it's not like these cards being limited to 150 MB/s per connector would be an issue, since the card can't send that much data to the motherboard and processor in the first place. Don't see the max 150MB/s per connector as a flaw.
Support for 300 MB/s or 600 MB/s would be useful only let's say when you're copying data from one drive to another on the same controller, without data having to go to the motherboard.  You mostly want 300 MB/s or 600 MB/s for most compatibility with all hard drives out there.
 
 

might struggle - and it's quite power consuming - but it probably will be fine

not really, a raspberry pi would be better than this.