How many triggers inputs do you want?
Triggering with pads and drum sticks?
Do you have a sampler?
I had a cheap Alesis IO with 10 inputs or something, but midi only.
@AdamJay recommended the Roland TM2 with A4. WAV, up to 4 sounds.
You can make diy pads.
More expensive, Roland Spd Sx, and the must with Handsonic HPD 20.
I have a cheap DD65 with pads but no wav samples, and I prefer my Wavedrum Global, hackable, but no wav samples hack.
Octatrack and Wavedrum