i'll second the Akai MPK-88, being a piano player, also. It can send and receive at least two streams of MIDI over 16 channels. i've had it for a few years and it's been sturdy, though i can't say i practice like i did in college. The pads are excellent for any live drums you might want to play as well as system control changes to any synths you've connected to it. The sliders are beautiful if you've a virtual B3, and the knobs are continuous, so you can twist away without breaking them. It's USB powered. And best of all: i plugged it into my computer and it worked right away without downloading a single driver.
You're in Toronto? If you ever run into Borys Medicky, tell him, "Hello," for me.
Bill Wolf