7600GS vs 6800 GS

For some games I'm getting this Christmas, I intend to upgrade my computer's video card.

Intel Pentium 4 2.20GHz
GeForce FX 5500 128MB
1GB RAM

Yes, I use an AGP slot. Before anyone tells me to get a faster CPU or convert to PCIe, let me just tell you that I AM. When Vista comes along, I intend to get a completely new computer. For now, though, I want to know which (AGP) card you think is better - the 6800 GS, or the 7600 GS? I seem to be able to afford both, and both are also pretty similar in pixel pipeline count and such. I've heard some people say the 6800 GS has a noisier fan, but I've also been told that a card from the GeForce 7 family may incur a bottleneck on my computer.

So, which do you think I should get?

As you're going to change to PCIe soon, I'd say get the cheapest. They'll both run all present games, how noisy they are will vary not only between manufacturers, but even between cards, as it's partly due to whichever fan was cheapest the week that particular card was manufactured.
FWIW, my 6800 ultra is completely silent.

I'd go for the 6800gs, after all it is technically the faster of the 2, the reason being is that the 6800 has a 256bit memory interface, compared with 128bit on the 7600, this gives the older 6800 a bit more grunt in the memory bandwidth stakes.