Suggestion for keyboard for MPC Touch

Am new to this entire studio set up. I have an MPC Touch on the way, but would like a keyboard that is compatible and semi affordable. I have been looking at the Akai Professional Advance line, but the MPK line is appealing too.

As I'm just starting out I'm sure there are others that may be better suited. Any suggestions on where to start. I know the MPC Touch has been said to be everything one would need, so looking for help.

Anything that has Midi ports or Midi over usb should be fine... are there specific features you are looking for?