Overclocking the PNY or Visiontech GF3 Ti200 is easy. The cooling fan and heatsinks that come on the card are fine, no need to replace them unless you really want to see how far you can get. Even then, all you need to get is a blue orb and some Artic Silver 2 paste/tape.
To Overclock, right click desktop and select Properties. Then Under Display Properties/Settings/Advanced/GF3 Ti200 Properties/Additional Properties should be a "Hardware Options" tab. This is where you OC from. Try going up a little at a time on the core/memory (like 10 or 20mhz each) and see how far you can get till visual artifacts appear in games. The first time artifacts appear, back off on the memory speed a little at a time till they go away. Once they disappear, you are all set.
If you don't have a "Hardware Options" tab or something similar, you need to use the "Coolbits" hack or a GF overclocking utility such as NVmax. I like Coolbits. Just do a Google search for it and you'll get all the info you need.
From what I have read, the Visiontech card will do at least 220/460 stable, which is just a little faster than a regular GF3. The PNY with faster memory has been known to hit almost GF3 Ti500 speeds (240/500, I think it actually made 235/515 or something close to that). Of course to get near this with the PNY you may need that Blue Orb and the Artic Silver stuff.
Done correctly, overclocking will do no harm to your video card (especially Nvidia cards). I have been running a Visiontech GF2 GTS OC'ed about a year now no problems at all. The GF3's you both bought are excellent cards, best bang for the buck (even at $200 dollars), and are made to OC.
Do some 3D Mark 2001 benchmarks with them at default speeds (175/400), then OC to 220/460 or higher and benchmark again.
You will like :)
After you get these cards installed, quit playing WFA. I don't need 2 more people kicking my ass :)
I know, you could kick my WFA ass using your old trustworthy TNT.
You are really gonna like your new video cards!