If you want more help then you should specify some parameters, cost, weight, power, user friendliness, etc. Other than that there are many good .46-.58 two cycle engines out there. Any will do -- pick the brand that you are most comfortable with.

There are fewer 4 stroke choices, but once again there are several good choices in the .52 to .72 range. Pick whichever brand you are most comforable.

Regardless of your choice you will need taller landing gear. The engines in the sizes I have mentioned all work best with a 12", or longer, props. The stock SE gear will not allow you to swing much more than an 11.5" prop. Tnt Landing gear has a taller gear for the SE.

Cheers!

Galen