*EDIT*: Perhaps that was a little harsh.
Fan placements in this are crap, if you don't want to spend too much on a case, I'd go with the Cooler Master Elite 330
You might want to consider the modular 500W
variation of this PSU. It's the same price, but believe me, once you've owned a modular PSU, you won't ever want a regular one ever again.
500W would still be more than sufficient for this build.
Good choice on the RAM.
Instead of going with a 750i and a GTX 260, I would go with a P45
and a HD 4870
. Not only would you not have to deal with the disadvantages of having an Nvidia motherboard, but you'd also get a slightly faster card in the HD 4870. Most P45s support CF too, so you'd have that upgrade path.