I think what you are looking for is a jumper. These are very affordable and should let you accomplish those goals. You are going to want to use a digital in device to read a 1 → jumper or 0 → No jumper. These can be used in a simple if-else statement to select which autonomous to run. How you choose to use them is up to you. You could assign one 3-wire port to one auto but that will limit the amount of autos you can have. You could also treat each port as a single binary bit and exponentially increase potential. Since the release of V5 these have fallen out of style but I still think they are a very redundant way to select your auto long before placing your robot on the field. I have seen enough wrong autos selected in haste when running late. 