RC-FIEND:
The easiest thing to build your first spad out of would be the 3/4" u channel (available at home depot-menards-lowes) found in the metal rod and sheet metal areas of the store.....ask someone for a 3 foot section of all-thread rod and you'll find the u-channel (actually called plywood edging). The downspout can be found at do-it-best hardwares (they can normally order it for you no problem if not in stock. Coroplast can be found at the majority of sign shops (don't forget to tell them you ARE BUILDING A PLANE not signs) for not that high of price. All that's left is to get your creative mind working and start building.
Here's a couple of mine with a coro fuse:
And a few of the downspout fuse:
If you want to build a coro fuse I can send you a couple sections of the downspout to get started...it's not that hard actually. The coro fuse pane I've got roughly 20 hours in the build but most of that is due to using poly glue on the fuse that takes a while to dry. The wing was build and finished in a hour or so.
Madd_Maxx