Thanks all very much for the compliments and I'm glad I could share something after learning a lot from this forum!
Hudson J1e: I used standard brown hardboard which comes in 4x8 sheets at Home Depot (it is 3/16" thick). Around $15 per sheet if I remember correctly.
Let me offer some lessons learned:
1. Give the hardboard a light sanding before paint to take off the "sheen"
2. I used basix latex primer and flat green paint - both of which you can pick up at HD for $1-2 in the decorator's sample size (infinite number of colors to choose from without the hassle of having quart and gallon paint cans hanging around)
3. Drill pilot holes for the LED housings (which are 5MM) before cutting the final holes
4. Use good micro switches and make sure the stem is long enough so it will fit through the hardboard. I used Radio Shack DPDT switches but they were pricey (~$5 each). You can probably do better over the net but it is nice to try them first for smooth action throws (I find some other mini switches are too stiff)
5. Get lot's of LEDs (I burned out a handfull with crossed wires and alligator clips etc)
6. Use nice stainless steel screws with finish washers for mounting to give it a more finished look (as opposed to drywall screws)
7. Everything is hooked up to Tortoise machines - and Ross switches - each of which are outstanding
Pensky4: Thanks for the compliment about it looking "professional". I was trying to make it look good like it came out of the pages of magazines like OGR! And the curved approach definitely frees up a l lot of space.
Hogmaster 1: The blue tape in the mock up was basic line tape from Staples. For the actual painting exercise, I laid down pinstriping tape (1/4") from a local hobby store (used for detailing model race cars etc.)