Hardware interfaced to mcahine. ( I/O's to be analog & digital )

how to do this and what language should i have to use
Hardware interfaced to mcahine. ( I/O's to be analog & digital )
Switches & knobs + lights

Using these inputs to read the state the graphics to alter in relation to the position of
valves or quantity.

Example:
A tank is being filled with water. The flow of water can be changed by changing certain
knobs or switches. This affects the rate at which the tanks parameters change. These may
be temprature, pressure, volume, level, etc. They are further dependent upont other inputs that are user defined, eg. heat, humidity etc which are set manually as input condition into the system

Further the systems grahics to indicate the level of water very realistically.
Model like water.
Should be able to simulate the tank being tilted etc.

One easy way to have analog inputs is the joystick port. For the graphics, I think I might start with some BMP or GIF images, and color them at runtime to represent water and such.

How many inputs will be needed?

thanks dear,
but can you provide me some working example