As long as you are considering a single slot cooler GPU, you are risking over heating. The 8600GT is a very poor card in term of performance.
Change of Choice: The 8600GT 512MB DDR3 looks cool.
Yes there is, but it would involve suggesting a PSU with a severe lack in quality. As a result, I won't be able to recommend one any cheaper.
Also: Could there be a chance of a much Cheaper Power Supply?