I'm glad to hear that you've had a good experience with the Hextronic's. I just put 4 of them in my Pico, albeit the analog HXT900's. It seems several people have good comments about them. At that price I admit I am a little concerned.

It sounds like you should put those 15's to good use. 8 oz for an engine setup with pipe sounds pretty good. If you build the finished airframe to 18 oz., add the power setup to bring it up to 26 oz, that would leave you with 6 oz for radio and linkages. Mind you, even at 40 oz the model would be light on the wing and have plenty of power.

I'm probably over computing this thing but it strikes me as though 50" span might be a tad large for a .15 even if piped. What if you reduced it to 43" span or 86% scale? I could do that easily if you're not an Illustrator guy.

David.