ORIGINAL: RCER88
Your TT with a 10x6 will do a good job.
Your ss30 either 9x6 or 10x5. your 30 if it runs well with a 10x6 might even pull a trainer.
Back in ''the day'' we flew goldberg eagles and kadet mark II's on Enya 29's with a 10x6 prop. My Enya 29 is still in a box from my ''trainer days'' So if built by the plans your 30 should fly a lt 40. It will not be fast and not to aerobatic but it will fly.
I would have a good pilot test it if you are going to run the small engine on it.
I will probably still put the TT on it, I just figured if the 30 would fly it I might try it. SIG recommends a .30-.40 2-stroke on the LT-40. I figured the .30 flying it a little slower might be better but either one has been pretty dependable. The TT .46 has maybe 2 gallons on it and has been used on 2 different airboats I built. The Enya is still breaking in on my test stand and has seen about 1 gallon of fuel.