In reference to figuring out a good engine to get, I was in the same boat for awhile. I hav ebeen running the Nexstar which comes with the OS 46FX and have no problems with it at all. Since I interested into the warbirds I decided to go after the P-51 Mustang and build the system around what I wanted, new radio and engine. So I talked with alot of the guys at the club who run different engines and found that the Evolution which comes with the Mustang RTF version is not that reliable. The Evolution has a bad tendency to stall out in flight and hard to start in weather below 0. Since up here in Canada we like to do a lot of winter flying I have seen that the OS engines handl ethe cold better and start alot easiear. I have opt for the OS engine on the planes I am going to get , since using them I find them easiear to adjust, more realiable them other engines and do not stall out like others. Do more research on the engine you are looking for, go to manufacture sites and talk to the club members. Most members will steer you in the right direction for an engine since they have had alot of experience in this field. I am always talking to our members about what to d and what to try. Only my thought but if you wnat reliable, stay with the OS engines, pay the extra dollars and you will have a good engine you can use in another plane when you want to advance on to the next level.