For portability, nice sound, novelty (almost nobody has ever seen or heard one), relatively low cost (compared with similar quality accordions), and a chance to see if you like CBA fingering, I think that the accordina is reasonable starting point. Think of it as a three-row, 44 note right hand of an accordion, with your lungs being the bellows. The breath needed is light (like a recorder or less), and it only weighs two pounds.
Marcel Dreux accordinas (accordinas.com) are played by a lot of the top European accordionists. A few members here play Marcel Dreux accordinas and the original Borel models that inspired Marcel Dreux, and I imagine you could get a lot of information from them.
Full discosure, I recently started a discussion about preparing one for sale (I have 3 slightly different models), but I've decided not to sell any at present. I wouldn't want you to think a was giving you a sales pitch. I am just describing the approach I took (also senior citizen at the time) when the idea of playing cba accordion popped into my mind.