Well that's what I'm saying. It doesn't have to take up $600. You can make a good setup for $250-$300. If you want to save money, get a big Rad, and then you won't need 2 loops IMO.
As far as mobo requirements, the only thing you need to check, is the CPU block, to make sure it comes with the mounting hardware for your socket. Other then that, no there is no Mobo requirements.