1. A part selector with 3 right, 2 left and 1 bass (auto and manual bass) parts. A button for manual bass on/off to play bass with midi pedal board. A mono/poly bass button. A button for left hold on/off. Probably it would also be good with a bass to left button (with right hand chord recoqnision) also for those who want to play left hand bass.
2. A B3-wannabe with full polyphony and easy control over the 9+9+2 drawbars. In worst case 9 physical quality drawbars with buttons to choose right, left and bass. In best case a complete set of 9+9+2 physical drawbars. Possiblity to chose sound variation for drawbars of theatre tibia, classical pipes and a couple of other organ sounds. 3 on/off buttons of the drawbar parts that should be layered over the standard parts. Of course also direct access to all other neccesary organ controls. Good leslie simulator or temolo when using theatre etc... A loop return output/input for the organ sound to possibly ad your own leslie sim with internal or external mixing.
3. Songbook/music finder with >2000 presets and total numbers limited by internal memory only. The songbook should adress registration banks for easy set up arrangement for a song with at least 8 registration buttons. There is no need for separate registrations and songbook. The registrations banks is the songbook.
4. >500 internal styles.
5. Support of >=1GB sample ram. Load akai samples.
6. Preferable 76 keys. Semi-weighted quality keys.
7. Dedicated up and down octave buttons for right as well as left parts.
8. 4 OTS/style
9. >=256 polyphony (+full poly for drawbars)
10. Support a couple of more foot switches than the standard 3 without the need of some kind of huge midi board.

Of course it should have a quite large wave rom with quality sounds and also very good drum sounds.

I would pay up to at least USD 6000.