Well firstly let me ask what you play. If you are someone who plays games that use Physx then perhaps it may be wise to stick with Nvidia however if you don't or you don't really care about eye candy you may also want to keep a eye on the 7970. The better value at the moment is the 670 however to be fair I'll provide a link to both sides of the fence as both are valid options in your choice. But yes I would avoid getting SLi.
Companies to look for:
ASUS: there directcuII cooler is very quiet and will provide excellent cooling.
There is also the MSI power edition card which is a decent option as well. The noise level is a bit high on the startup but this is because when the computer boots the fans spin backwards to brush off the dust that is left on the card. This stops after around 30 seconds. The card runs very cool and has the possibility for great overclocking
I would think the cards will come out in a little longer then a few weeks maybe months at this point I would expect around April, May and possibly even June. So I would ask myself if I were willing to wait to see what is about to come out. Or quite possibly wait for the new product to come out and get the current generation at a cheaper go rate.
Hey I want to thank you all for your comments and opinions I really appreciate the feedback. Right now I'm playing black ops 2. and I know it doesn't take much but I like my games to be as smooth as can be and awesome looking as possible. maybe $350-400 is too high for me.. anything close to being as good in the $250-300 range?