dnicky2288

The linear potentiometers are called Magnetopot from Spectra. These are driven by magnets. They are slightly expensive but fit this purpose nicely.

When you have a servo valve amplifier board that takes care of the PID system in an analog setting, you don't need to tax the Arduino with more things to do.

The parts are recycled pneumatics and they are not easily sourcable. If needed, look up double-acting pneumatic valves with at least 1" bore and 12" stroke or bigger. Make sure your connectors and fittings are matching. There is no fixed parts list to achieve this since you can do the same thing with a multitude of parts!

Low pass filters can be simple to make. You just need to use a resistor and capacitor. However, you will need to apply the RC equation to get the voltage as smooth as you want.

Because pneumatics can provide much more torque, stability, and velocity. You woild not even want to think of a screw drive linear actuator. That would not be enough to simulate the motion profile of many planes.