Stearman
This Guillows kit is built very light. Mine was built for control line. A .061 is more than adequite. You might even consider an .049. I'm not sure how long such a light kit will last in use. All the 1/2 A planes I fly now were designed for R/C. I reinforce my air frames so a few extra "Gs" won't hurt them. Most usually weigh in at 22-26 oz.
The large prop is to slow the engine. I have a 50" Cub with over 15 air hours on it with this setup (Cox grey 6x3 16,500 20%nitro). My 42" Citabria has about 10 air hours on it ( 5.5x4 Cox grey 17,800 35% nitro). My son has a 72" Piece -O-Cake running the 6x3. None have overheating problems. If you have overheating problems use less nitro or run more head shims. Other club members that have had problems with Norvels have asked for my help after observing several seasons of trouble-free flights.