The reason I was only going for the 7600GT was mainly cost. Didn't want to spend to much as I will get a new system in the next year or so. Also my PSU isn't the best and didn't want the cost of a PSU upgrade as well.
My current system is below:-
Abit NF7s V1.2 & AMD Athlon XP3000 CPU at stock speeds (Nforce2 chipset).
2x 512Mb Corsair PC3200's at stock settings.
Geforce 6800 256Mb AGP graphics card.
FSP 400-60PFN 400w PSU (+12v = 15.0A)
Windows XP Pro SP2 with latest updates.
I would of thought a 7600GT would fit my system nicely. I did want either a XFX 7900GS or 7950GT but those are silly money and my PSU wouldn't cope. The PSU also rules out the ATI X1950's.