I would get a 52 four stroke if you have the money. I sold mine to a friend and it was a real sweetie.

You are gong to find that the senior is the easiest trainer there is to learn on bar none. Very gentle flyer.

With the 52 you will be able to have some fun with it once you learn to fly.

If not the 52 I would go with an OS 46AX. My 3rd choice would be an FX. The AX is the best running 40 size engine I have ever had my hands on.