MoonClipper
XS400 Enthusiast
This is my recommendation as well. A titled frame will probably run you $150 or so. That seems like a lot, but obtaining a title in other ways could run you more than that.Find a frame with good papers and just use your parts.
I'm sure someone will recommend the Vermont loophole, but that doesn't work anymore. It's only available to those who live in Vermont. It would probably be easier to go through the process of claiming it as a abandoned vehicle.
Unrelated note, my bike is indeed a 5 speed