Get low profile memory/Ram so you don't have to worry about installing your Cpu cooler.
I have a Sapphire vapor X 7950 and I like it so far.
Don't go cheap on the power supply. Get a 600W-760W gold rated or better power supply from Corsair or Seasonic. I have a Seasonic X-850 850W PSU an it is doing its job well. Also chose a modular one if you can. Corsair's HX or AX series will work or Seasonic's Platinum
or X-series will also work.
---And to give you an idea on temps of the Sapphire Vapor X 7950 card, mine runs at about 30C idle, and about 54C gaming in 1080 in my CM Storm Scout 2 with all 9x120mm case fans installed at full blast.