Ok the reason I asked you the questions was to get a scale of the project at hand. The cheapest power you can use is likely to be air or hydraulic cylinders. You can power them with an air compressor or a hydraulic pump. I do not suggest straight air power unless an hydraulic secondary cylinder is used to dampen the air cylinders operation as air cylinders tend to move rapidly and all at once. Air over oil will work as well if an orfice is placed inline to restrict flow.
Now as to sensors, a really cheap and available analog sensor is to use the oil pressure sensor from a car that uses an electric gauge, it is simply a pressure variable resistor, it would work in an A/D or POT circuit.