I had a Sig Kobra and LOVED it. I flew mine with a Evolution 36 and 9x7 prop. It screamed! Get the Kobra, you won't be sorry. I went with the Evolution because it is a powerful, inexpensive, light engine that fit very well in the plane. If you don't mind shelling out the insane price for the OS 32sx, go for it. I'm sure it would be an excellent power plant for that plane but there are other engines out there that cost less and still perform well. Either way, it's a really fun plane!

Brian