8600GT Overclocked vs 8600GTS

Hello, my video card just died and I desperately need a replacement.

This is my current setup:
AMD X2 4200
MSI KN9 Platinium main board
RAM 2x1Gb 6400

The dead card is my beloved eVGA geForce 7900GT GDDR3 256Mb, I was able to play even Crysis with this setup.

I dont have money to spend and I dont live in the US, so I'll have to buy a 2nd hand graphics card, this is what I can get:

XFX 8600 GDDR3 256Mb GT + Evercool Turbo2 Fancooler
or
XFX 8600 GDDR3 256Mb GTS

Both used for about 6 months.

So its basically the same card, one OC'd by software plus a bigger fancooler and the other OC'd by the manufactured, I'd like to hear your opinions about which one I should get.

I care more about which one will last longer than its performance, since its about the same, I like the bigger fancooler of the first offer, but I'm not really sure.

One more thing, I'm still scratching my head about my dead card, I dont play THAT much, and the computer case has several fancoolers around, one is just right there in front of the graphics card so I dont think it was overheating. I was ALWAYS using 2 CRT monitors tough, does it stress the video card that much? does it have anything to do with the card failure?

The card now shows black and white stripes at bootup and windows loading screen, after a while loading it shows the blue screen and locks up. Works with no drivers or in safe mode only, so I'm guessing its the video RAM, I dont see any physical damage on the card though.

Thanks.

You are right, getting the 8600 would be a step back. I'm looking at a 4670 and the difference is about 100$. I'll see if I can reach that, otherwise I'll get the 8600GTS like you said.

Computer parts are extremely expensive over here, the 4670 costs 345$ new, its crazy compared with the pricetag on Amazon of 90$, on Newegg is even cheaper.

Thanks.