How about a little CAP 232 for the YS?
I just love the combination of the YS .63 in my 40 sized GP CAP 232 (not to be confused with the GP ARF CAP 231EX). With a 13 x 6 APC and 25 to 30% Nitro....whoooooie!
If one HAS to arf it, I have also been watching a guy at our field fly the small Yellow Aircraft CAP 232 with a Saito .56. The little Saito pulls it with Authority (the plane is a great flyer with no bad habits I've seen) and the YS .63 ought to be just about insane enough in this one to be fun!
Lee