Another update:
I did the only good (least worst) solution that I could think of, and have made 4 successful flights. I went with the OSMW recommended Cobra electric power system, and the performance is beyond phenomenal, Unlimited vertical at 1/2 throttle, and I will very rarely ever use full throttle. This is WAY too much power for a sport flier. I bet with well over a pound of very draggy floats on it, that it will still have quite unlimited vertical.
It weighs 5.5 lb with the Cobra system and 4S 5000 battery (which is also too much battery - I land at 8 minutes and still have a bunch left).
The bad news is that is has an extremely nasty habit of ground-looping just as the tail comes up and before the rudder becomes effective. I have built over 50 planes, and have never once had a problematic ground-looper, even with warbirds. I will have to try different techniques to deal with it, since adding right thrust, advancing the throttle slowly and keeping the tailwheel on the ground as long as possibly didn't do diddly squat to remedy the problem.
Once it is up in the air, if flies very nicely. Like a high wing pattern plane. Inverted is kind of squirrely, but hammerheads and knife-edge are very nice, plus it slows to a floating crawl on landings, especially with flaps.
Because of the vicious ground loop issue and the fact that it was pretty much non-feasible to power it with glow, as built, I regret ever buying this thing, and doubt I will buy another of theirs, unless they come up with something revolutionary.