1. Gaming Series™ GS800 — 80 PLUS® Certified Power Supply
Positives
*Great Built
*Upto 85% efficiency and that's great!
*Roughly "flawless" PSU in this range
Negatives
*None
Check out- Gaming Series GS800
2. CoolerMaster GX 750W
Positives
*Superb Voltage regulation
*over temperature protection
Negatives
*
80 plus website doesn’t list this power supply

*Noise level at +3.3 V and +5VSB outputs were above the maximum allowed when pulled 600 W and above.
Check out- CM GX 750W
IMO you should have now have no doubt in selecting the better one.i.e. Corsair GS800. Its way better especially for hardcore gaming which you're gonna do

In a lower price bracket, a better option than CM one would be Seventeam ST-750P-AF, but if money is not a concern, GS800 is the one for you.
BTW check out following links, they may be useful to you in selecting right PSU for you-
*PSU Watt Calculator By CM
*Another PSU Watt calculator