I would get the 7900GT because later on down the road if you ever want to upgrade you can upgrade into another 7900GT for SLI, however, if you get 2 7600GTs you get to replace both of them.
"Truth is violated by falsehood but outraged by silence."
"Mastering others is strength, mastering yourself is true power." ~Sun Tzu
"Ad Astra Per Aspera"
"Our greatest glory is not in never falling, but in rising every time we fall." ~Confucious
"The true measure of a man is how he treats someone who can do him absolutely no good.” ~ Samuel Jackson
“Omnis vir est fortunae faber”