RE: kit for .26 4 stroke
Stinger 10. I have a couple, looking forward to the same sort of option you are.
I also have a Clancy Big Bee that I"m hoping to get around to building soon, probably go with a 2stroke of the same displacement range.
Ace still offers their little Ultimate, I've heard they can handle anything from a .15 to a .40, you might try one.
Best wishes,
Dave Olson