Here's my two cents worth!!! Try the weadeater 18 or 21 CC converted to Gas/Glow Hybrid these will start on "either direction" so you don't have to purchase especial props, just invert the prop side and the starting rotation on the rear engine, these engines converted to Gasd/Glow Hybrid should weigh less than 2 pounds and would be a great substitue for a 60 or 90 size plane; on this forum some mentioned thar they were selling these engines for $ 35.00 I will try to locate the info from back dates also there was some one on e-bay selling these little gems, another great deal to try is this one www.duropower.com they have a 26 cc engine that is a Zenoha replica from china for $49.00; But best of all if this is your "DREAM PLANE" I'll plainly tell you "DON'T SIT THERE GO FOR IT BUDDY" there is nothing like building your dream come true.