About 15 years ago a few of us from the old ocremix chatroom (and others) collabed to animate Brian Clevinger's "8-Bit Theater" webcomic.
Voice actors/directors Mack Devin & Edwyn "Omahdon" Tiong (aka the second Black Mage actor) recruited some of us recently to voice VG Cats' tribute to 8BT.
For a site dedicated to nostalgia, I figured it wouldn't hurt to get nostalgic.
The strip is here: http://www.vgcats.com/comics/?strip_id=65
The voiced-over video is here:
It was a blast getting the band back together. Let us know what you think and be sure to check Mac & Omahdon's pages linked in video's description!
I think he meant "live performance?"
Based on what you're saying, I'd get a weighted keyboard of some sort. If it's basic and only has a few (or even no) sounds, that's probably all you need. I'd hold off on any kind of MIDI controller until you find a need for it in your workflow (e.g. "I wish I didn't have to use the mouse to automate this..."