We use the Waves C1 compressor on most percussion, and the Renassance Compressor when we really care about the type of compression e.g. when we are compressing the entire rhythm section or on other critical parts. Start with the C1 and go to the Ren Comp if you think it sounds better and the part is significant.

C1 is pretty effecient although it doesn't have the nicest interface ever.

Make sure you don't over compress with a long release - you'll get a very loud click at the beginning or when you start your sequencer. If you have this problem your release time is too long or you just need to turn down the track and back off on the threshold/release/ratio a bit (or just bounce the track down and pick a loop from the middle and use that loop in the track which will save you some CPU anyways).