ZDZ 80 would work well in a Ziroli Bearcat. It just depends how fast you want to go and how heavy you build it. Those two projects are miles away from each other in cost and the amount of work, but if it was me, Id' go Ziroli. Everything you need is easily available and you will end up with a real nice plane that fly's well. The Royal plans, canopy and cowl are available on Ebay but .60 size planes are to small support alot of scale stuff.