they are a good engine just built a little stout for compared to the saws you will come in under 5 lbs for the engine.Anything in the 1/3 scale size will fit the bill.
http://www.chiefaircraft.com/cgi-bin...33Edge540.html
or if that is to much these are fun and with that engine just a whole lot overpowered ARR ARR ARR
http://www2.towerhobbies.com/cgi-bin...?&I=LXDPC6&P=0