So I am thinking either Ravenscroft or Pianoteq Stage software and an iPad Air 2 or some sort of small Windows tablet. In my initial looking it seems like the software approach will yield a better quality sound. I need nothing more (other sounds, DAW, etc). I need a simple setup for gigging that produces a good quality jazz piano sound either in a hardware module or software library playing on either iPad or Windows small tablet.
I am trying to keep costs down below $600.