Hi,
Are you looking to build a trainer with a .60 motor, or are you looking for a trainer that is a ".60 size" (72" wing)? If it is a 6-foot wing that you seek, then definitely take a look at the Big T from
www.JKAerotech.com. This company sells foam/coroplast combat planes, which are incredibly durable (ask me how I know...see my name?). This is a trainer that is made of the same material, and is EXTREMELY light...manufacturer claims 4-4.5 pounds. Can you say light wing loading??
I modified the plane a bit by adding ailerons, as it was designed as a rudder/elevator only plane. I also fiberglassed the wing center section, and added yardstick spars into cutouts in the wings. With these additions, she still feels incredibly light. Best of all, JKAerotech recommends a .25 to power her, but I used an old OS 40FP, and she is very overpowered! I use this as my camera/spy plane too, as she can easily haul herself and the camera in to the sky with just a .40 bushing engine.
You can add as much dihedral as you want by sanding the root of each wing panel before joining them. On high rates (which I enjoy on all my birds), she will roll axially, loop insider herself, and fly inverted more easily than any trainer I have ever flown (I instruct).
I highly recommend her. Below are pics of mine....done up in a Super Decathlon scheme for enhanced visibility.
-Dan