In reality, your options are limited. Creative are by far the biggest supplier in the world & whilst you can go with Asus or Aopen, you'll often end up with Creative technology on the card. Money no object? Auzentech.
I'm not saying for a second you should discount Creative, but if you do go with them, make super sure that you can get the correct drivers - when Vista came along, Creative refused to offer updated drivers in an effort to force users to buy new cards. A user - Daniel-k, hacked the drivers & posted them up for any Visat user to download, Creative threatened to sue him, the whole sorry affair got into the I.T. press & Creative were shamed into backing down.
Just be sure you're supported with Creative.