There are very few good reasons to put drums in your case. Drum modules are more expensive than buying a drum machine. Those modules will also need additional modules to be cohesive. If you have 8 drum modules going, you're going to need a Eurorack mixer with at least 8 inputs. You will also need a sequencer with 8 triggers available. So it's a substantial investment for something that can be replaced with a $300-$400 external device. Your audience isn't going to care if all of your drums are coming from the case or a drum machine.
There ARE good reasons to have modular drums if modulation is something that's extremely important to your own personal sound in abstract music. But for 99% of people... it's JUST a drum sound.
The 1010 Music BitBox is a good compromise if you want to stay inside the case. It can also be triggered via MIDI if your sequencer supports MIDI OUT. It's possible to run one TRS cable from the sequencer's MIDI out to the BitBox's MIDI in. Without giving a full tutorial on MIDI there are caveats of course.
There are smaller sample playback units that will work just fine as well. I'm speaking of gear I know and I'm familiar with.