Tim, the engine mount that Tom provides will fit up to a .32 size engine. I only added a 1/4" spacer to set the prop washer at the front of the cowl.
The kit comes with another engine mount that Tom suggest not using (he thoughtfully provides another one). I used a pencil tip soldering iron to push out the installed blind nuts. The firewall did not need to be beefed up for my .36 heli engine.
If you go to a .40 size engine, then you will need to check the fit of your own engine mount. You'll need to mount all rc gear in the tail to balance out a .40 size engine.
The glow version will definitely be less expensive as the electric versions that have good performance are all at at least 1000 watts of power.
I think a OS .32 or similar will make this a great fast plane. Not like a Nelson powered Quickee but still fast.
If I had a Jett .40 or a Nelson .40, I'd put it in there just to push the envelope of the plane.
