I tried to honor the "60 size" design and put a Saito 91 four stroke on it. MyAUW is 6 pounds 14 oz. I did some lightening: 4-40 control linkages, dubro pull-pull, and HS-225 servos for the elevator, and left the pants and fairings off. Flies light on those big wings. Knife edge was limited with a low pitch prop, now a 14-7 APChas it flying great. As for servo reversers, I have a Spektrum- and they don't like them, so I slaved CH5 to the elevator using mix #5 to the trims come across. The DS-821 servos from the Spektrum DX7 box seem more than adequate for the ailerons and rudder. I Rebuilt the tail so that the smaller servos were back to back to avoid linkage geometry errors. Flies great, although I haven't had a lot of calm days to precision trim the beast. Will climb out of hover, but I think you need the Saito 100 or 125 (same weight as my old 91) to POP out of hover like a foamie!