Don't listen to Adrian, he is building a super secret electric Bipe!
Mike, it depends how much time you want to put into getting the YS put in, and getting it set up right. Do that, use the right fuel, and I would say go with the YS. If you just want to get out there flying, the Saito will be quicker and a little more user friendly, but I've seen them have plenty of issue's also.
There should be plenty of folks here who could hook you up with a good motor at a good price I would guess.
Chris