That size motor would work well on the 35" 3DFoamy.com planes. They are very good for indoor flight, but can fly outdoors as well. Check out this video of the 3DF Mini Sukhoi:

http://www.3dfoamy.com/Videos/3DF_msukhoi.wmv

I think it would be a little too small for a 40" foamy. My Pro Giles had a Hacker A20-26M, and it was an awesome motor for that size plane with a 3S lithium battery.