Well Seth is pretty easy with Cammy (medium difficulty)
Fight the first round as usual, then on the second round hold back and let him jump at you; immediately counter with her dragon punch motion (forget the name of it). He'll do it a couple more times, just keep countering with DP motion. He'll throw sonic booms for a bit, which is good since it builds up your bar, and he'll eventually try to jump in at you again (counter with DP motion).
Sooner or later, he'll either die from the attacks, time will run out, or he'll try to walk at you, whereupon you just unleash your revenge meter against him.
C.Viper, on the other hand... I have no fucking clue how to work her.