For the belts, you can just use the common link belt which you can get at Harbor Freight. I found it really helped smooth out the machine. I think the standard V-belts tend to take a set over time, and this causes some vibration. Also, check the setscrews on the pulleys, my motor pulley was very loose.
The machine was made by a company called 'Elephant' in Taiwan. In fact, my knobs all have the elephant logo. Their website, for your reference, is elephant.com.tw
Some parts are available directly through Jet, though a lot of these parts are probably interchangeable with other brands.