I'm thinking of buying a new Merc or Tohatsu 5hp or 8 hp to do double duty to power a 10' Achilles inlfatable and as a rarely used kicker for my Mako 20. I used to have an old Mariner 8 hp that worked great for both boats -do you think I will be disappointed if I drop to 5 hp ? (I'm seduced by the the lower weight and lower price of the 5hp)