Hi, Erik.
Just come across this thread....
What a great looking boat the S19 is! Are you as happy with her as I am with the CBL?
I have the same outboard problem with "Four Sisters" - the CBL being just, as you know, a "breathed on" S19 with knobs on!
From new, I fitted a 4hp fourstroke Yamaha. She copes ok with the extra weight and it gives me enough power to fight tides while towing a broken BayRaider (!) and,of course, a reverse gear - very handy in all sorts of situations from backing off of a sand bar to stopping her dead in a hurry.....but, it is impossible to swivel the Yamaha around in the well. It can only turn 10 degrees or so off centre, meaning that most, if not all, steering is done with the rudder when under power. (Top speed about 6.5 knots, by the way) I would have thought that the Honda would have room to rotate 180 degrees, if you tun the prop away from the rudder i.e. anti clockwise. Is that not so?
She also has 90Kg of lead ballast bolted down inside the cabin which adds stability and helps keeps up her momentum when sailing to windward in a chop - but makes her more difficult to shove around hotel car parks.
All this weight + cruising equipment must adversely affect performance and her balanced lugsail is less weather than the usual sprit rigged gunter so I dare say your S19 will sail rings around me most of the time. I like the Lug sail for its many advantages (which I need not go into here) and for the way I can sail past most BayRaiders on a downwind run - until they hoist a spinnaker, that is, and so I dare say that the S19 would give them a run for their money on any point of sail.
Why do you want to change the rig? More performance? Easier rigging? Some other problem?
If you really want to change the rig it might be possible to use a one-piece CF mast and a fat head BayRaider mainsail. How much of an advantage that might be is debatable. It would certainly cost a fair bit and you would no longer be able to store all spars inside the boat when trailing.
If you just want more sail area in light airs (and more string to play with) you could follow Graham W's example and fly a mizzen staysail.
A way around the mast stepping problem might be to use a tabernacle. I wanted to do that to make shooting bridges possible but I would need to change from an unstayed mast - not an option with a balanced lug sail - and I would need very tall chainplates to clear the cabin top!
Let us know how you get on.