I was planning to to the mockup with foam board since that's easier to mess with, but yeah, that'll be the first step. Hopefully I can get the engine in place tomorrow for that.
Twere I to get a welder I would get this one, since I've heard good things from Tim:
Amazon.com: Hobart 500487 Handler 125 115-Volt 30-to-125 Amp Arc Single-Phase Wire Welding Package: Home Improvement