I ordered the plans for the Simple Single today. It will be a good introduction to the process and after that I'll tackle the twin if I still feel up to it. I'm sure I'll have questions in a few weeks. Till then I'll scope out parts-so far the cheapest I have found for cylinders is a guy on ebay who will sell 2 cylinders and pistons for 10 bucks and you get to choose from a variety of exhaust/porting options. I'll wait and see what the plans call for. Thanks!
Derek