as plugs, i do use the stuff in waves4 (expensive) and the fishfillets bundle a lot, they are great and free... http://www.digitalfishphones.com (all 3 fillets are great for drum manipulation)

The best gate is the mouse gate. Take ten minutes in the volume editor and edit the volume line on the tom tracks, or use strip silence to regionalize it and then do batch fades for the in/outs.
For kick and snare, a gate will work (before the compressor!) but sound replacer works better. Replace the kick and snare with a clean sample from the same kit with Sound Replacer, and then mix the original track lower than the replaced track. my 25cents