Hello everyone, its been a while since I posted here on this category. Anyway, I'm about to buy a graphics card this payday

, and basically I need your help and opinion.
I'm pretty much limited to 5K budget, and I'm considering these options as per
PC Express' Pricelist. I'm considering the following graphics cards:
ATI
PC HD2600XT 512ddr3 128bit dvi - 4330
PC HD3650 512ddr3 256bit dvi PCS - 3750
PC HD3650XT 512ddr3 256bit dvi PCS - 4760
Nvidia
Inno3D 8600GT 512ddr3 dvi 128bit - 4870
Of the three ATI video cards, do you think I should just go for 8600GT? I've been reading a lot of good reviews for the 8600. Unfortunately, I contacted PC Express and they reported that they don't have any stocks for this card, which is why I considered the ATI cards since the 2600XT is available. Do you know of any other store that has a wide range of video cards available?
Also, I've been hearing some stories about issues with 2600XT drivers, are any of these true? or do they exist only on the AGP...? One thing that I need to clarify though is that I'm not going beyond 5k as a budget since for me spending a tad of money is way ridiculous. I'm not a hardcore gamer, just casual by the way. Any help would be much appreciated.