From Montego Bay to Ocho

Is it too far to have one of the recommended tour companies take us from Montego to Ocho?

Depends on your time in port. It's about an hour and a half (without traffic) from MoBay to Ocho Rios (So minimum of 3 hrs round trip), so you'd have to make that call. If you have a 5 hr port time, then yes, it's too far, if you have 8 hrs in port, then no problem.