The Fantom and the Leitra together. The parts are so itemized for the Leitra I can't say for sure how much it cost. Of those over 100,000 copies of the drawings for the Fantom, few were ever completed because, as with so many "Plans" you buy, it doesn't really tell you how to build it. Many of those that were finished bear little resemblance to the drawings.http://www.westsystem.com/ss/wood-epoxy-longevity/
If you go to a boat shop, you can find West System epoxy to put a finish on your wood. You get the 105, I'd go with the slow hardener but you can take the faster one if you like. You can use the straight epoxy 2:1 with the hardener. The straight epoxy will have that glossy finish. Ask for a UV additive. I was thinking of suggesting the hotcoat, but maybe I'd be getting you into more than you're ready for. If you use the clear epoxy you can put a photo, etc. on the wood and you'll see it right through. "Tubesteak Tracy," upon whom "The Kahuna" of 'Gidget' was based, got his nickname from resining his surfboard with a napkin from the beachside fast food outlet offering "Tubes, Steaks. . . ." It's best to print out whatever you want to put on there on ricepaper, or something light. Any little pattern you put on the wood will show through.http://www.amazon.com/Yasutomo-Kozo-Pap ... B000AMQFRKhttp://www.westsystem.com/ss/
You can do the hotcoat instead with the polyester (Fiberglas resin from Pep Boys, etc.) for greater reliability, you normally use just 1-2% hardener but with acetone I'm told to go 3%. Mix a little acetone in the resin BEFORE adding the hardener, up to a 1:1 ratio. Polyester is rather forgiving, it's easier to do this with it than with epoxy. You can get a woodlike surface. Or you can use the regular polyester without acetone and 1-2% hardener. It'll give the same glossy finish as the epoxy and it'll be cheaper. You'll also want the UV protectant to mix in.
Oh, if you really did use 1/8" plywood, I'd suggest picking up some 6 ounce per yard to 10 ounce per yard fiberglas to put on there. The fiberglas is clear when the polyester or epoxy is applied, you'll see the wood. You can even fit some pieces of corrogated cardboard inside using the resin as glue and putting fiberglas over it, this will really strengthen the hull without adding much weight. Literally with a light core of some sort you might add 7% of the weight but make it 3-5 times stronger. 6 ounce per yard means that it weighs 6 ounces per 3' x 3' square, the proper amount of resin would be 1.5 times that weight, so literally if your surface is one square yard you add about a pound this way.
If you want to color it you can do it by mixing the paint into---- well, maybe I shouldn't start a rookie off on too much. Although maybe just a gel coat (Polyester) or facecoat (Epoxy) after wouldn't be so hard. Either way will cover anything you had on there before the resin.AND DO TEST PANELS BEFORE YOU DO THIS TO YOUR REAL BIKE!
Make sure you can make it work before you risk the finished product.http://www.westsystem.com/ss/projects/
You don't even have to use plywood, you can buy the 1/2" EPS foam (White coffee cup material) from the lumber section of the hardware store in 4' x 8' sheets same as plywood, then glass it as I said, except either 2-3 layers of 6 ounce or 1-2 layers of 10 ounce on the outside and maybe just 1-2 layers of 6 or 1 of 10 inside. Epoxy only, don't use polyester, EPS will melt. It's good to put some sealer on EPS to keep it from soaking up your resin, maybe straight latex paint or mix a little plaster in to thicken it. If you sand it smooth it's easier to create a flat smooth finish. I suspect even though it would be lighter than the plywood car it would be stronger.
You can cut EPS with a razor blade, coping saw, bandsaw, but the best is with a hot wire. Tells how to make one here:http://www2.swaylocks.com/node/1019361
Once you're good at that, you can learn to make surfboards.http://boardcad.org/index.php/Main_Page