Outboards for sailboat
I owned an O''Day 25 with a Mercury 9.9 longshaft for 12 years. Highly reliable engine, relatively quiet and cheap to maintain. Johnsons are great also, but consider problems of dealer support with OMC going bankrupt.
I never owned a 4 cycle, but imagine that the hassle of an oil change would balance the hassle of mixing engine oil for the 2 cycle. I almost ruined my engine once when a guest forgot to mix in the oil when hooking up a new tank of gas.
I hope your 26 footer is a slippery racer if you''re going to power it with a 4 - 5 HP outboard. My O''Day weighed about 4800 lbs and the 9.9 was not exactly overpowering it.
Fair winds and friendly harbors,