Can you link the exact model, since Gigabyte seem perpetually sold out, maybe I will give one of those a try.
The cheapest one. No OC, no GHz-Edition, no Vapor-X, no nothing, because some of those only do 550kH/s even when overclocked like hell.
Do you know your power draw on those since you undervolt? I have a box that has three 7970's and when I use a kill-a-watt it pulls 400 from the wall for one, 700 for two, and 1020 for three. It works out to roughly 300 watts per card with the remaining 100 watts for the system.
For a system with 3x7970 it pulls 625 Watt from the wall (in total!).
Although, their stock is up 23% this year so far. Coincidence? Who knows. 
