Thru the years while recording drums, occasionally I will get a bad track. Sometimes it's due to a drummer hitting the mic ( ouch! ) or a mic will slip on the rim etc. for this I used to use an Alesis D-4 drum module and the bad track ( if it at least has a signal ) can trigger the D-4 module. The D-4 has 99 kicks, 99 snares, 99 toms, and other percussion sounds. I record with a Neve board, and a Mackie HDR. The Mackie HDR has a removable hard drive cassette which slides out of the HDR then slides into my MAC G-3. I discovered a plug-in that does exactly what the D-4 does, only easier to dial in and is much more versitial. I downloaded the demo and was instantly sold. Its called Drumagog http://www.drumagog.com
Over at the KVR forum there is a group buy where if they get enough buyers, it can be purchased for half price