If both cards average over sixty frames per second, wouldn't the more inexpensive pair be my best option?yes, the minimum frame rate and the max will be higher on the 570 pair.
you could also try a pair of 6950's
and welcome aboard!
AMD Radeon HD 6950 1GB Video Card in CrossFire - Benchmarks - High Quality AA and AF :: TweakTown USA Edition
I absolutely love mines too. But the HAWK ones are nice! I like the "retaining arm" that helps keeping the PCB stiff...I absolutely love my Ti 560 Twin Frozr II in SLI set up, mainly due to the performance they deliver for nvidia surround gaming as well as how well they overclock and the scaling performance increase from that.