Many 25" motors available.-----Location is everything.----Know of a 25" 8 HP now used on a 19' boat with great success.----Extension kits may be available.----New motors use up a lot of beer tokens.
Many different regulations.----All depends on your location.-----And the towing rating of vehicles is for when they were new.-----Many older ( rusty ) vehicles should be inspected before a " hefty " towing job is attempted !