For quick and dirty sensing our team has had a good experience with
anything VEX, largely because of their robustness and ease of mounting and wiring. The ultrasonic rangefinder, limit switch, and bumper switch all required very little work (assuming things like female-female PWMs were on hand).
As mentioned earlier, any 1K to 10K-ohm potentiometer should work well. You can use a
shaft coupling to attach it to a shaft.