I was just like you poorkid when I first entered the hobby. There are so many engines out there to choose from. I began with the o.s 40LA i my .40 size trainer and is now in my low wing sport model (Tiger Sport). I strongly recomend this engine, it is easy to start, smooth power and most importantly is fairly cheap. If may not have the power such as the the 46fx but it is fine for what it was intended to be used for. The needle valve at the back of the engine is also very handy.

Good luck