RE: Need Advice On A Couple Of Guillow's Planes
It was difficult enough to do a good job of putting a pulse receiver and an actuator in a Guillow kit way back when. I think you'll find yourself re-engineering the kit a lot to handle the loads of modern R/C flight and finding a way to get a servo/receiver tray and battery box into the fuselage with decent access. You'll need good firewall to take a radial mounted engine and a couple of rails from it going back to behind the trailing edge to support the servo tray and battery box.
If you must try this, start with the Cessna and think about it as a very sedately flying R/C assisted freeflight.
Good luck.
ps: anyone else have some ideas to help here?