The max size for a cruising couple depends in part on how the
boat is set up. In other words, how easy is the
boat to handle and sail.
On our
Manta 42, all lines are led to a
single electric winch. The
jib is a self-tending, camber spar arrangement rather than a
roller furling. It tacks itself. There is a
boom brake and a vang standard.
If you are going to live aboard, then you want to consider YOUR needs, since guests will only be an occasional event. I wouldn't worry too much about how many people the boat will sleep at one time - rather, how comfortable will it be for you and your wife/companion. If it works for you, then your occasional guests will manage for the short term.
Hope this helps.
Harriet Eisen
s/v Perseverance