As I understand it, indiana.joe is an actual bass player, as in a bass guitar, in a jazz band. And what it appears he wants to do is to play his real bass guitar with his hands, and then use his feet to control a pedal board which would be MIDI'ed to an arranger keyboard to activate "single finger" chords on the arranger. And also as I understand it, he wants to do this and not have any drums or bass with the arranger's accompaniment because he is playing the real bass, and his band has a real drummer -- so he just wants to use the arranger to play backing keyboard sounds because the band's keyboard player left the band and they have not been able to find a replacement keyboard player.
If this is the case, then as I and others here have previously said, this set-up would be less than ideal, because hitting a single pedal, to activate a single key by MIDI on the auto-accompaniment of the arranger, would only play a major chord. You'd need two feet to play a minor or a 7th chord, and a volunteer would have to come in with a third foot to play a minor 7th chord. And of course, this would not allow for playing any of the more complex chords commonly found in jazz music.
To me, all that comes to mind is using the arranger's built-in sequencer to pre-record the backing keyboard accompaniment for each song, and then indiana.joe and the drummer would just play along to these background recordings of each song. In this case, the arranger's sequencer could be used with an auto-accompaniment, which would allow for a fingered mode to be used while recording (since this keyboard part would be recorded separately, it could be done with hands and no pedal board would be needed), and fingered mode would allow for many of the more complex jazz chords. Or, auto accompaniment would not even be needed, depending on the keyboard skills of indiana.joe or the drummer, as they could just simply play the accompaniment directly into the sequencer just as if playing the keyboard live during the song. Then, they would just play along with this sequencer recording of the keyboard accompaniment.
While recording such a background, or "mini-arrangement" (as noted above), you might want to use the rhythm/drums so you keep time while recording, then turn the drum track off during playback when you're actually playing along with the recording. But of course, playing along to such a "rigid" pre-recorded accompaniment and chord progression like that means that the background just keeps progressing through the song if you make a mistake, and it does not allow much room for improvising any chord or structure changes during a song. Tempo changes would also be difficult, if not impossible. And you would need to make sure the keyboard parts being recorded and played back had a strong rhythmic quality to them, because indiana.joe and the drummer would have to play along and follow the beat of the pre-recorded sequence on the keyboard, and if there were any slower, pad-type sustained chord parts, it could be difficult to track the timing of the keyboard during those parts, unless the keyboard has a clearly visible "beat counter" flashing light.