Arduino controller interface

Hello, I currently working on a switch and trim box for a flight simulator. I was hoping to get some answers on whether or not an arduino would be suitable for this application. I ultimately need 20 digital inputs for momentary toggle switches I have as well as 4 analog axis. I can probably get away with 12 digital inputs but in the end I need the arduino to be the go between of the switches and pots and the computer. I would be great if I could get the arduino to show up as a game controller or HID. Could someone please help me understand what I would need to make this happen or point me in the right direction if it is even possible? :-/

An Arduino Duemilanove has 14 digital pins and 6 analog pins. A Mega has 54 digital pins and 16 analog pins. So, the Mega would have the required number of digital pins. With multiplexing, the Duemilanove would, too.

I need the arduino to be the go between of the switches and pots and the computer.

The Arduino can send serial data to the computer. It is up to the computer to recognize that this is happening, and read and use that data.

I would be great if I could get the arduino to show up as a game controller or HID.

You would be. But, unless you have more skills than you appear to, and add some additional hardware, that won't happen.