Bachus,
When I had a similar setup working a few years back:
I had the lower keyboard SPLIT, LH sending MIDI ch 1 for left voice on PA2XPRO AND chord recognition.

RH of lower KB sending MIDI ch 4 andplaying the RH voice of PA2XPRO

The upper was for RH voice's 1 and 2.

MIDI pedals was for bass in style channel, can't remember MIDI ch but was easy to do.
This worked super with all mt registrations, songbook, and all the styles...Only extra work I did was on some registrations/styles I created my own version with RH3 voices I wanted on the lower.

As to a quality 76 MIDI kbd, I used a CME UF70 (sold it a while back) but you can definetly find a good one , be sure it has ability to do split (2 seperate MIDI channels)