he said 7600 gs vs 7600 gt. the 7600 gs does not have 20 pixel rendering pipelines. you are confused with the 7900 gs. (which you stated in your post). if a 7900 gs was cheaper than a 7600 gt, i think there would be a bit of a problem.
id go with the 7600 gt passively cooled card.
"The GeForce 7600 GT extends its clock speed advantage over the GS as we move to memory, with the GT sporting GDDR3 memory chips clocked at 700 MHz. GDDR3's a little indulgent for the more affordable GeForce 7600 GS, which is typically equipped with GDDR2 memory clocked at just 400 MHz. Both GeForce 7600 series chips have a 128-bit memory bus, so the clock speed gap gives the GT nearly twice the memory bandwidth available to the GS."
clock speeds are also a fair amount higher
DEF go with the 7600gt. you wont regret it