Where can I get the buttons for the right side of the steering wheel controls?

Can I make them all push lock button with the light like the cruise control button has?

I want to make them for my amplifiers, volt meters, line output converter, etc

 

Whether you can re-purpose the controls to do what you're thinking is kinda beyond me, but here's the "How To" thread on adding the OEM audio buttons to the wheel.

https://www.chevyhhr.net/forums/how-tutorial-library-21/adding-radio-buttons-steering-wheel-1912/

 

Yup, sounds pretty involved. They are not separate wires for each button, pressing each one changes the resistance value of the circuit, which is then interpreted by the radio or bcm.