Most people here would probably recommend MSI, Asus, or Sapphire branded cards. Powercolor is definetly a brand to avoid since they are typically loud despite being cheap (who'da thunk). Asus probably offers the best quality coolers, but they're also typically on the expensive end because of it. MSI has also been doing a really good job in the "cool and quiet" department lately. And I've always been happy with the quality of Sapphire cards. This MSI card
features dual fans which should keep temps and noise low (as is typical with MSI). At $100 after MIR it's also the best bang-for-the-buck until Dec. 20th.
I wouldn't worry too much about who offers the highest factory OC as all these cards can probably be pushed to around 1100MHz core without increasing voltage. What you really want is a good quality cooler on top; more heatpipes (or just heatpipes in general) is always a good indicator of a better cooler, having dual fans doesn't hurt either. You can simply google various cards for reviews and/or read newegg.com customer reviews. I'm sure others will chime in that have hands-on experience with specific brands/models of 7770's also.
Main: i5-3570K, ASRock Z77 Pro4-M, Asus GTX660 TOP, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
HTPC: A8-5600K, MSI FM2-A75IA-E53, 4TB Seagate SSHD, 8GB 1866MHz G.Skill, Crosley D-25 Case Mod