the PS3 has a much better CPU and graphics card than the 360.
I wouldn't say that. Some people say the xbox has a better processer due to it having 3 general purpose cores vs the PS3 only having one general purpse core. Some say PS3 has a more powerful cpu because it has 7 SPEs as they call it, although these are not as powerful as a full general purpose core. The only way to find out is waiting until they actually come out, and then compare performance of the same games on each one keeping in mind that the settings may be different. As for the GPU, it is still something that cannot yet be proved. Some say the 360 one is actually better, some claiming the PS3 has a better gpu. Most agree though that no matter what gpu is better, it will only be a minor difference. All in all you can't say one is much better than the other until they come out.
As for the main question, I would get the Phisx card over the xbox 360. Unless you have an HDTV, then it may be cool looking into. Or you either don't have a good gaming computer or cannot afford a good gaming people. PC gaming is better than console in almost every way possible, the one thing consoles have on PCs is cost. Unless you want the most of these new consoles, then you have to get an HDTV too......Monitors looks much better tvs.....My two cents.