Check with Mike Hanks. He's built a few, and is pretty much the voice of Authority with the Walrus.

mailto:kayakbuilder@harbornet.com

I build one, but went too big and got very little use out of it.
I would not recommend it for the group you are helping. At least, not the original Putz method. Mike has done some in skin and some S & G.
Tom Yost has a couple that would be good choices for a small group such as you have there. You can use ply frames and wood stringers to make it cheaper. Many have done this and come up with very nice boats.

Rehd