RE: Marutaka/Royal Bearcat
The plane builds very light. I'll have to go weigh mine but you'll be surprised how light the fuselage is (very little blocks are used, it's almost all planked)
I put in Century Jet Models retracts with the tank in the wing (wing is thick at the root) so you don't have to worry about connecting/disconnecting air lines. I use a servo for tail wheel retract.
Mine has an ST .90 two stroke in it. I'll probably switch it out for a .91 4 stroke just to swing a bigger prop (big cowl). You don't need a "big" engine as the plane is lightweight.
The kit is a head scratcher to build (very little info on how to do things) but if you have a few kits under your belt it's a no brainer.
I'll post pics later (I'm at work)
Don