For ages I wanted an electronic drum kit, but never had the room. I ended up getting a Yamaha DTX Multi 12 and a Korg Wavedrum (on clearance). Here's my little setup, from in the case to ready to play. The DTX is simply awesome. I love the fact you can load your own samples, although I wish it more than its piddly 64BM of user RAM.
In that little setup I have 18 triggers (12 on the DTX, 2 snare, 1 bass drum, 1 hihat splash, 2 hihat pad) plus the Wavedrum. Beyond the DTX M12 and the Wavedrum, here's the rest of the hardware.
* Snare: Used Roland PDX-6.
* Hihat pad: Used Roland CY-8.
* Hihat pedal: Used Yamaha HH64.
* Bass drum pedal: New Yamaha KU100.
* Main stand: An old Roland one from an SPD-6 I sold to make way for this.
* Wavedrum stand: Used, top half of a vintage snare stand.
* Other hardware: A variety of Gibraltar clamps and mounts.
* Monitor amp: Roland Mobile Cube,