I saw earlier that so many new sim builders have difficulty getting started because there are so many options for I/O that it gets confusing. Everything from analog, digital, rotary, etc. to how to hook up the pots. Take a look here as this might be a quick and easy way to get started without a mountain of money. Scroll down about 3/4 down the products page. Hope this helps.

http://www.atsimulation.com/atsimulation_003.htm