Hey Pro
One caveat about the Oxygen8 and Ozone. Despite being touted as MIDI interfaces, they have no MIDI Ins. So you cannot plug another keyboard into them to drive software. Instead the Oxygen8 and Ozone have dual MIDI outs, which I find less useful. You should be aware that Edirol also has small USB keyboards and these have MIDI Ins and Outs, plus more controllers.
Clif