34 degs C during heavy gaming of Just Cause 2 is not hot at all. My i7-920 (OCed at 3.82 GHz) runs at 42 degs C during Call of Duty. Otherwise, like right now, at 29 degs C. Cooled by a CM V8 cooler with the base polished (some refer to it as lapping) flat.
I have heard that one single top quality video card is a better value for money than 2/3 cards in SLI/Crossfire. Consider this in your decision.