Slow Poke Good second plane?
I would not discourage you from the Slow Poke, but if you are building the kit (don't know about the ARF), the Sport 40 is notorious for needing nose weight. Mine balances OK with an OS 70 four stroke, which is not way too much power, and gives the needed heft. I have mine hung out towards the end of the beams on a Dubro isolating mount.