Likely all will work fine as the KT133 chipset supported AGP 4x. Cards that are AGP 8x will work with 4x too. The only card that might give you trouble are some of the GeForceFX 5800 and 5900 as they draw a lot of power and your power supply might not be up to par. A good GeForce4 Ti4200 would be a good card for your system.
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