If you are having to buy an engine, I would veer away from the Saito 80. Although it is an extremely good running engine, it is heavy. I would either get the .72 which is also an extremely strong engine for its size or get the 100. The 72 will save you about 3 oz over any of the other engines avalible for that plane. It should balance with that motor with everything in the fromt of the plane. Mine has a Saito 100. It weighs 3 oz more than a fellow club members with a OS 50sx. Mine has twice as much power. The saito 100 and the 80 are approx the same weight, but the 100 has way more power and doesnt cost very much more. If I were to buy an engine for it I would get the .72, but I also live at a very low elevation where the air is dense. I dont know about the geography in IL, but If you live below about 1500 ASL you should be fine with the 72. If you live about 2200 or less, you can use that motor with 30% nitro and you should still be alright. If you live much higher than that I would go ahead and get the 100. Plus if anything ever happens to the funtana, you can always throw that 100 in a 60 size airplane and not have to buy a new engine. I would put a 14x4W APC on the 72. I run a 15x5 wood or 16x4 APC on my funtana depending, but i have made some changes to the landing gear, but many people have run 15x4W APC with no problem. One thing you have to remember on this plane is to keep the throttle setting as low as possible. Besides that they are beautifulr flying airplanes. Good luck with yours.