What is a good dedicated Physx card for me?

I am going to be upgrading my PC to run Nvidia stereoscopic 3D soon and was worried about framerates. I have a GTX 275 by BFG and an i7 920.

In Resident Evil 5 I get like 200 FPS but the game doesn't support Physx to my knowledge. In Batman Arkham Asylum, my framerates are at an average of 147 fps without Physx but only 50 with high Physx (ran at very high settings, no AA, 1080p). This is fine in 2D but I figure a dedicated Physx card would vastly improve my performance while still being on the cheap side. After all, upgrading to 3D is expensive.

My question is what would be a good card to achieve this? My budget is around $130 but obviously the cheaper the better, while maintaining high performance.