great choice for a system and if you shop around its hands down the best performance for the money (besides the ram, id go with crucial ballistix, great a64 performance and a good price; 2-2-2-5 to boot!) you should easily be able to oc both the proc and your 6800gt to the speeds of their higher priced counterparts. but what about hdd? best choice: go for two raptors in raid 0, they'll scream through bootup and app loads. (if you need more storage later, jsut add a third, theyll run even faster in a 3 drive array!)
enjoy ur system.