This is the Build i didnt put much time in looking for the parts only about 30 mins if you have any advice or changes to this build that would help me alot. Also he is probably going to be buying this computer by this weekend.
Good choices ( though personally i would go AMD in this price range, like for the same price you could get an AMD PII X3 clocked at 2.8ghz, so you get an extra core, and quite possible unlock it it for 4 cores at 2.8ghz for the same price as that dual core, if not cheaper ). Also that ram is fantastic, i got the timings lower then the stock settings and it runs great
As it supports crossfire/sli for a future upgrade if you ever decide to go that route. But im not sure if the ECS model does or not, it doesnt say, so it probably doesnt. BOTH MOBO's are quite similar, just one offers better longevity and options for the future. Plus i know the EVO comes with ACC, the ability to unlock cores so if you want to try it on your callisto, you can see if it will turn into a quad core.