DIY...Really?
With no offense toward anywone...
Do you gentlemen who advocate the OP building his own computer really think someone who wants a computer "jampacked with memory ... to run windows xp" is
currently capable of even ordering the parts, much less assembling them? Time is money, and by the time the OP
invests enough time to learn enough about computers and the virtues on one processor over another, etc. to build one, he would probably end up spending more "money" than if they just bought one from a reputable supplier.
To the gentleman looking for a computer, XP can only access and use slightly more than 3 GB of memory, so "jampacking" it with memory is a total waste of money.
May I suggest you start by talking to the folks at Sweetwater (
www.sweetwater.com)? They offer a line of reasonably priced computers especially designed for recording. I'll post links to other manufacturers at the end of this post so you can also check them out.
You will also want to be able to tell whoever you talk to what recording software and hardware you intend to use, and how you intend to use it. Recording a 100-piece symphony orchestra will
generally requires a bit more computer than what would be needed for recording just guitar and vocals in your bedroom.
BTW: I've been making music for more than 45 years. I've been in the IT game (mostly software, but a lot of hardware) for more than 20 years. I could quite readily build my next music computer, or, in the same amount of time, I could write a song or two, learn a bit more about Pro Tools, or work on adding a few more drum licks to my "lick box". So, next time I need a new music computer I'll just make a couple of phone calls, then sit back and wait for the big brown truck.
Here's some other computer vendors:
http://www.reyniersaudio.com/
http://www.pcaudiolabs.com/
http://www.adkproaudio.com/
http://rainrecording.com/
http://www.shop-sonica.com/default.cfm
http://www.visiondaw.com/productcart/pc/index.asp
Good luck...