After more research, I think I've answered my own question. From what I've read at various places. Powercolor is a reputable vendor of reliable ATI stock cards, nothing special but nothing bad either.
I decided a Powercolor 5850 at $289 is probably not any better or worse than most other brands and purchased one. As a bonus, the powercolor version of the cards comes with a code for Dirt 2 on Steam which I sold to someone else for $15, driving the price of the 5850 down to $274 when it's all said and done.