The AG17 airfoil is thin and undercambered like the airfoil of the full scale Sopwith Pup. The AG17 has a very low drag coefficient which is minimum (Cd<0.007) at a lift coefficient of 0.12. This airfoil would tend to minimize the power required to push the Pup to the top speed you desire. The coordinates and polars can be found at:
http://www.charlesriverrc.org/articl..._allegro2m.htm