The cutter I use to cut FFF and Depron sheet has a 2 1/2 wheel (razor sharp) . FFF can be found at Lowes or HomeDepot or most any building supply stores. The best is Dow but the others can be used. Plastic film on one side must be removed or put where glue don't go. (OUTSIDE) . Go to
www.rcgroups.com and check out the scratch built foamies. Theres many to choose from and easy to build. Theres a Piper Pawnee agg. plane that is on my must build list. 48" KF wing with much dihedral that the guys that have built sal they fly great. KF wing is simple to make and flies like a Clark-Y. Check them out.
Ken