hi/low rate is a good idea on any sport model. On models that large you'll need a high end radio. You need to be able to mix duel elevators, expo is more useful in the larger stuff. Twin especially a 38 in any scale is more like a third twin. I though the point of the PTS is it your 2 planes. So this would be a third. 30% would be insane to do as a third model. don't even think of a twin of giant scale for at least a yr. Go for like a 60 sized cap or extra 300 suikoy or YAK. After that get a hobby co twin star to get acquainted with twins