Whats your flying weight going to be, the way I see it is if you are going to be 9 lbs or more you will probably want something with more power for all out 3D performance. In that case you might want to consider a bigger engine, I have a Aeroworks Yak 54 120 size and it will come in around 10-11 lbs. A Saito 150 or 180 would be perfect for it but those things suck glow like no tomorrow. And at about $20 bucks a gallon for glow versus $2 a gallon for gas its hard to compare. I have the MLD-28cc gas motor for my plane and it weighs the same as a Saito 180, it has 2.8 hp and will swing a 18x6 no problem. So if its going to be under 9 lbs stay glow, but over go gas.