the manufactor does mather btw, but if you didnt know that then im not gonna explain it would be waisted time.
for buying a new card you should only look to card that cost what you want to spend on them and that can work in you current setup.
if you know a little bit more then you start looking at preformance vs costs
and if your a pc junkie then you dont care about the costs, and just buy the best or the latests

Beta: Latin for "still doesn't work".