I don't see why a CZ52 wouldn't work perfectly well for you.
7.62x25 may be relatively small in diameter, but it propels the bullet pretty fast so it is actually not all that weak.
Much of the military surplus ammunition is corrosive, which means you will need to wash your gun soon after firing to prevent the salts from corroding it.
As far as defensive ammunition, I think practically any ammunition would get the job done, but not many manufacturers make 7.62x25 hollow points if that is what you are asking.
Read the FBI's PDF at http://www.firearmstactical.com/hwfe.htm if you want to know the best information there is on terminal ballistics. It dispels a lot of myths.