2600XT or 7600GS or 7600GT

Hi

I'm wondering which video card is faster the 7600GT or 2600XT? Also is the 2600XT a little bit more faster (e.g. extra 5 fps per game than 7600GS) than the 7600GS?

Which brand should I buy, Xpertvision 2600XT sonic edition ddr3or HIS excalibur 256mb turbo edition ICEQ ddr3or sapphire 2600XT 256mb ddr3

Thanks.