I use a Roland TD10 module with PD120 snare, KD120 kick and PD9's & PD7's for toms and cymbals. It works great. If all you need is MIDI, any one of the lower end Roland kits will do fine. They all will provide all the MIDI info you need to record. The advantage of the TD10 is the 8 outputs as I am using the onboard sounds. Once I get the MIDI track edited to my liking, I let it "play" the kit while I record 8 tracks. I end up with mono tracks for kick, snare, hat, ride, crash 1, crash 2. I record the toms to a stereo track. Go here
music and click on Believe.mp3 to have a listen to the results.