If you want to hit DDR600, get G.Skill RAM. it is guaranteed to get at least that under 2.5-4-4-8 timings, and at 2.7 to 2.9 volts
I would get a Seagate or Western Digital hard drive instead, they are much more reliable. personally I prefer Seagate.
also, don't go cheap on the PSU. if it goes bad, it can take out the system with it.
go for: Antec, Thermaltake, Enermax, OCZ (OCZ ones are rock solid) or Ultra (they also look really good). and 500W is a good amount. try and get at least 480.
also, you might want to consider the X2 3800+
it is also very overclockable, based on the Venice (it is a dual Venice really) it will perform a little bit less than the 4000+ in games (although they're more graphics card dependant) but will skyrocket when you multitask