BalsaUSA Stingray40
The wing airfoil is semi-symetrical, but is not very fast. A .61 will vastly overpower a Stingray. If you want a lot of power an OS.46FX will make it a pretty speedy aircraft. It should be close to fully aerobatic with the possible exception of sustained knife edge without a lot top rudder. The OS.52 4 stroke does very well at 5000' ASL.