Well, Rod Tait is a nice and friendly guy, and I bet he'd be happy to answer each and every one of your questions about his design.

But, roughly, you will need your length of kayak plus about a foot of fiberglass - x2 because you have to do the inside, too. It has to be wide enough to go around the hull, of course. Often people use 6oz glass for the outside, and some use 4 oz for the inside, BUT, this varies A LOT from person to person. Ask Rod what he recommends.
You won't need to make too many fillets for a stripper, so a minimal amount of colloidal silica or the like will be fine. Some wood flour - or just plain sanding dust - added will make for a more natural color.

You can get epoxy and glass pretty cheap at Raka.com or Duckworks or often for more at or CLC or West Marine or various other online distributors. There are many brands of epoxy, which all work, though some may be better than others. Try Google . . . .
Your local marine chandlery will likely also carry epoxy products, but not necessarily glass in the quantities you need.

You might check out Laughing Loon kayaks, too, for Rob Macks tutorials. Plus, of course, Rod Tait has some good ones at his Orca boats website.

Good luck!