RE: giles g-202
I don't know which G-202 you are referring to. If it's the Wild Hare 35% G-202, the 80 will be plenty of power. You would also find it to be a very well made plane. I know I did.
I don't have any info that would relate to the AirWild version, but I believe theirs is a G-300 and a 100cc engine is suggested.