I was mulling the motor around today and came to same conclusion as you.
I totally forgot that I have Super Tigre .10 and a 30 amp ESC that was I was going to throw in my Yak 54. Since I bought these 2 planes the Yak can't make an appearance for a few weeks
I just ran it up with a Master Airscrew 10x5 on a 3S 2650 20C. 24.7a x 11.3v = 279.11 W. Ive already run this motor in my other now destroyed Yak and it will definitely fly the Champ. These are great motors. All right then...moving on to mounting it.
The battery tray and front hatches are roughed out. I ordered 50 magnets today, not that I need 50 for this plane but K&J has 8mm x 6mm x 1.5mm on sale for 6 bucks. http://www.kjmagnetics.com/proddetail.asp?prod=ZB5
I'll just make the wind screen from balsa and make it part of the battery hatch.
It's shaping up.