There are many dozens of these motors/gearmotors available for less than 20usd, often less than 10usd, on the web. Often found in microwave oven platter drives, BBQ rotisseries, metering/dosing drives, etc.
They are generally spec'd cw/ccw. The nature of the design. Random start in either...
Trying to locate a source for inexpensive 1/8 pitch (miniature) roller chain sprockets. 8 to 10 tooth. Bore not important. I'm generally familiar with #25 chains and sprockets on up. Below that range I can't seem to find much ready information on dimensions and availability and I wonder...