I might aswell bump this so you see it...
The 2500 isn't any better than the 2400. It's clocked slightly higher but performance wise you won't see a difference. I don't have much experience with Intel boards, but I know that for that price you could get one from Asus or MSI with more features.
As I said, it would be worth upgrading to 6 or 8gb of RAM. As I also said, I would recommend buying a better graphics card. In general, the graphics card should be the most expensive part of the computer.