is money really not an object, morbo?
good choice on AMD as u won't be wrestling with upgrade issues that intel processors & their many pin versions have. plus for the same amount of performance, AMD is cheaper. just make sure u have ample cooling for the processor. maybe water-cooling? <img src="/ubbthreads/images/graemlins/think.gif" alt="" />
as for RAM, yes as bean said it dual channel & make sure the board can support the latest RAM technology. that way, u have less worry when it comes to future upgrades.
as for HD, since SATA hard disks are just a little more expensive than normal IDE/ATA (about RM30 difference at my place), it's not something out of your spending power to own & going RAID on it will be preferable. after all, most motherboards now have RAID controllers.
talk about motherboard, morbo, think motherboard first. that together with the processor will be the most enduring part of your system so u may want to consider stability, upgradibility, & the built-in technology. if u don't have that many cards to plug in, just go for a mini/micro-ATX board.
& as for sound, bean has good taste. <img src="/ubbthreads/images/graemlins/up.gif" alt="" /> i also recommend creative soundcard but only if u have matching speakers to go with it. otherwise, 5 channels of audio will go to waste if u're only using 2.
people keep having problems with ATI cards. over here at my place, the source is always power supply units, which do not provide stable enough current for the graphic card. yes, ATI is very susceptible to this. at least 450W.
as for case, no point in getting a flashy one if u're going to tuck it under the desk or the system will be in your room where nobody is allowed entry. i say just use any old case that u have in hand, so long as it provides ample space for ventilation & upgrades.
sorry i can't be of much help.