Basic requirements would be to have a position (or force) sensor on each side stick and along with an actuator each connected to the controller.
The sensor is already in place as part of existing device so you would need to add the actuator.
As mentioned earlier research RC (model aircraft) servos as a possible actuators since they are a reasonable priced and the right size.
Do you have access to a pair of real Airbus side stick for this project?
If not ask your brother to 'borrow' a couple, one at a time though
