replacement Joy stick and buttons....

To all the people who know .....where can I get replacement buttons and a new joystick for my Neo cab? Here is a pic of it......

MVS Cab

where do I get the parts, about how much should I be looking at for price, and are there types of parts to avoid(i.e. generic parts?) thanks in advance.....

Happ is cool and you can pick the parts up if you want being as though they are in Elk Grove.