We used this to get a dozen buttons easily. It uses standard joystick drivers, so nothing to load on the Driver Station.
http://smile.amazon.com/Reyann-Arcad.../dp/B00UUROWWK
Regarding input methods:
I presume that you will be using standard joysticks to actually drive the robot. That is where analog input is most useful.
Everything else is mostly digital input (on/off). So, you need some momentary contact buttons (turn on when pressed, turn off when released) like the arcade button, and some latching buttons (or switches) that are either on or off, and stay that way (great for selecting between various autonomous modes).
If you want to get fancy, you can have some buttons with LED. You might have a spin-up the shooting motors button, and when the motors are at the correct speed, the Shoot button lights up. Ditto if you integrate it with vision (when your vision system determines that you are lined up for the shot, the shoot button lights up.
I could see using an analog input to control the speed of a shooting motor. You would then want to display the value on the Driver Station. I see that more for calibration purposes, and not for actual game use - try various motor speeds. However, simple up/down buttons work for that too.
Note: If your Driver Station fails prior to a match, the FTA will give you a basic clamshell DS. Those work with standard USB joysticks. I have no idea if they have the TI Launchpad drivers loaded.