nice setup, similar to a fair few others and not seen any mention of issues.
as mentioned if the o/s isnt 64 bit then you'll only get 3/3.5gb usable out of you're 4gb.
can drop the gfx card to the oc, over the oc2, unless its on special offer.
maybe change the hard drives to the western digital 500 aaks versions.
abit ip35-pro motherboard may be worth a look.