Hey Coop:

I would go with the smaller engine if you can, but you do need a reliable engine which ever one you use. Keep the CG at the recommended point. You can always move it back when you become more proficient at controlling the plane. If you are just learning keep in mind that the SE is a highly acrobatic plane, it can be a bit squirrelly ie very quick, but a very nice flier if you keep the control throws low at first, no more than 3/8 to 1/2 inch on the ailerons and 3/4 to 1 inch on the elevator. If you can use exponential on your radio use plenty 50 - 60%. Once you get used to the plane you can increase the control throws.

By the way I use a YS53 on mine and has plenty of power. Good luck and have fun