I suggest building with ailerons. Think it's better to fly 4 channel straight off sice most glow planes have ailerons.
Also if you learn how to fly without ailerons, I bet you want to have them when you get more confident and want to wring out the plane more.

Just for curiosity, what PT40 designs are, and have been out there. I started with a PT40 ARF 5 years ago, it was a nice plane.