Dont bother with SCSI, it's over kill for a desktop system. Just use Serial ATA. Look at around a 3.2ghz LGA P4 as they are the best value for money. RAM depending on what mainboard you use would be Dual Channel DRR 400, there is the option of 533mhz but at double the price is a speed increase I couldn't justify for the cost. If you want a quote let me know and I'll see what I can do for you once you know what you want.
Hehe just read the post above Wise geek words.