TY dan for the words of encouragement.
Not chosen the specific bike yet for the project, but IF I have to go with a new bike, I think the Hollandia Holiday Men's 26" bike will be it. Yes, it's a Walmart bike...but it is steel, looks burly enough to handle the motorizing, and should be fairly simple for a learning project. Here's their link: http://www.walmart.com/ip/Hollandia-...-Bike/16539708
Now, I'm off in pursuit of vendor reviews. I don't want a customer service nightmare!