As a single card solution, the 7950 would be better with 3GB of 384 Bit VRAM. It easily overclocks to beat the 670 and 7970 and performance scales very well to larger resolutions, especially with high levels of AA enabled. Currently AMD is leading in triple monitor (Eyefinity) gaming.
If you are going to add a second card in the future, you'd be better off the the 660 Ti as it has no microstutter issues with SLI. Nvidia cards are also the choice if you are going to play in 3D. It has hardware Physx and CUDA if they are of importance to you.
As for the issue of GPU temperatures and fan noise, it really depends on the cooler provided by the different manufacturers. Look for user reviews of each brand of card at Newegg and avoid those with a lot of noise/heat complaints.
Personally, I got the Sapphire 7950. Overclocked to 1050Mhz core and 1450Mhz memory, it beats the 7970 for only ~$300. At stock voltage and has never exceeded 60 degrees. Blazing fast, maxes settings at 1080p on all my games except Arma 3 and Crysis 3 (Very high).
At this performance level all you really need is 1 card, so I chose the 7950 and never looked back.