Hello I'm a programming student and I just learned about Arduino recently while searching for ways to control my radio cars from my own computer programs.
After looking into some of the products offered I found myself somewhat confused as to what I would want in order to achieve my goals.
What I want to do:
I want to be able to connect my remote controls to my computer and "drive/fly" them via my computer.
I feel confident that I will be able to handle the programming side, or rather that I will be able to have fun while exploring different ways to do this 
So I would like to be able to connect wire up controllers with 4-6 buttons and 2x 8 directional controllers.
Optionally I would also like to be able to receive some input from other devices, but that would be a expansion project for later. Still I would like to avoid having to a bunch of new equipment later if I could buy one and use it for both purposes.
What I believe I would need:
I would need to create a device which can output varying degrees of voltage (input strength for the stick) and optionally the capability to read incoming voltage strength on a number of ports.(what's the correct term for input slots?)
That way I can scan the incoming signals, and from that produce output to the user.
Then take user input into the program and send it as input via the remote control parts and into the rc plane/car.
A pre-made program making me able to control the RC unit is not needed.
So then my questions are, what equipment do I really need?
Are my assumptions about my needs wrong?
Thank you for your time 