A 920 at 4GHZ, if it's a D0, should be controllable as far as thermal goes. That H60 should be able to keep the temps in check. But holy mother dude, 480's are like black holes of power consumption and your room will prolly go up a degree or ten when you fire up a pair of those. 
Still though, props for that much WIN.

Still though, props for that much WIN.







GTX 480's are just... that way I suppose.



