4" wheels may be scale, but they are big enough to make it tough to fit them in. I used 3 3/4" wheels and I think they look plenty big. The skill level needed for this plane is about normal for a warbird. It's not a floater like a Hanger 9 ARF, but it's not as bad as some others. As far as a third, fourth, or whatever, that's hard to say. Maybe your first four planes were LT40's. I'd say it would be good to have warbird experience with a bit lighter warbird, then step up to the Hellcat.