The 55ax will be about right. The plane is much heavier than advertised. Comes in about 6.5 pounds with the 46/55 size engine. I flew mine with a TT46 and then a Tower Hobbies 75. The 75 adds a lot of weight up front and needs about three ounces in tail to offset. It is not a floater with that combo, but vertical is unlimited and it really scoots.

I recommend some aftermarket one piece landing gear. The rest of the plane is sturdy. The wing is thin and the control surfaces are small so this is a good pattern/speed plane not a 3d plane.

Mike