Based on the OP’s leanings toward the real deal Hammond, I’d go with the XK-5 as the main board and add a lightweight keyboard with good onboard sounds. The CK61 would be good, and by now you can get a used YK61. Good pianos, EPs, etc. Placement on top of the Hammond. Basically, a traditional organ player setup without having to fiddle with MIDI.
Another way to work it would be a Hammond XK-4 on top, CK61 on bottom. Or, there’s a CK61 / MSolo combination for weight but not the aesthetics.