For the drive system, I started with an old paper shredder gear motor that I used for a few years. It was nice and small, but it made too much noise. Last year, I switched to an automotive windshield wiper motor that I bought on Ebay for $8.00. The new motor is whisper quiet, but it's larger and more visible. This is not a problem as the porch is dark and the wheel stands behind a treasure chest that hides the motor nicely.
The original design also had no stand. I would run a bolt between the wood decking on our porch and attach it with a wingnut thru the bottom of the vertical stand, but that grew tiresome. A few years ago, I added a stand with some slits in it to simulate decking. It is way easier to store and set up now and you don't really see it anyway.