GTX cards replacement

I don't know what really happened, but after a shortcut in my 1000W power supply, my two GTX cards are dead (GTX480 + GTX570) (of course, the power supply is dead too).

I have dried my eyes, replaced the power supply, and now starting to consider buying new cards.
So, why not switching to ATI cards ?

I have potential budget for two HD7950 cards, but I'm a bit afraid since I heard about ATI drivers instability under Linux (at least in the past).

I use Ubuntu as OS (10.04 TLS). Could someone advice me if it is a good configuration for GPU computing ? (including oclHashcat, of course)

Thank you very much.
no issues with AMD drivers for me in ubuntu x64 11.10. i'm running 4xhd5970s with catalyst 12.2. remember NOT to install SDK and you'll be fine