If you want a stiff wing - get some of that iron-on carbon fibrer tape - and wrap a 1/2 strip clear arond the wing overlaping in the center - and use low temp iron to stick in place and then glue with oderless CA.

I would not sheet the wing with balsa or anyting like that - to heavy. Also a little hard to sheet as they come from a mold and don't have the shucks normally used to compress the sheeting into place - I guess you could use a vacume bag method if you have access to the equipment.

Just cover with lowtemp film over the CF or paint with laytex, etc.

If you want a real nice finish - cover with silkspan using water base polyurathane to stick it on - then sand and paint - losts of work for a quick little plane to bang around - but hey it's up to you how much time and effort you want to put into it.......