Brands don't mean much when it comes to hardware (most stuff is just Nvidia's reference design with a fancy sticker), but they do make a big difference when it comes to support. I suggest investigating a company's support before making a purchase. Do they have a toll-free number you can reach? Do they have a support forum where questions are responded to in a timely manner? What is their return policy and warranty terms? You might never have to use their support, but if you do, you want to know that they're there to help you.
Also, you can pretty much forget about overclocking much (not that you were). Most manufacturers are selling a wide range of "factory overclocked" cards, so you've got a pretty good idea that if the chip would run at a faster speed, it'd end up on one of their more expensive boards, and the only chips on the budget selections are those that they couldn't sell at a higher price. Of course, once the product line matures and yields of good chips increase, that sometimes isn't the case, but on any new cards these days, if the chip'll clock faster, they've already done it.
