There are no perks, but the weapons and settings for each class pretty much have the equivalent of several perks applied. There are other tweaks as well, all with the alleged purpose of making the game more "fair."
There are also a bunch of different versions of promod, and lots of people make their own tweaks.
It can be tons of fun, but have fun trying to get into a real promod server without a bunch of stuck up loser douchebags giving you shit constantly or kicking you off the server. <--- so for this reason, maybe it's cool that we are getting one. Of course, it will attract a bunch of loser douchebags.... but we can kick them