If you're talking about "Physx," then here is a list of cards that support it:http://www.nvidia.com/object/physx_gpus.html
Also, I wouldn't suggest any card specifically for Physx use. Although I do like Physx in games that use it well (Batman: AA, Mirror's Edge, etc.), paying extra money and using up a PCIe slot in my computer isn't worth it to me. If you want to use Physx in games, buy a decent nVidia card that is capable of running it smoothly. And I can't recommend a good graphics card without knowing the rest of your computer, including your monitor and its resolution, and your power supply.