I have planned to make connection as per the above circuit diagram. But when I to config 4 motors for the Z axis, the RepRap firmware just allows me to config only one motor for one axis. How do I config all these motors

How can I purchase Duet 3 mainboard 6HC from India?
Is there any way @dc42 sir?

Thank you for the suggestion @Phaedrux . I am using 6 NEMA 34 stepper motor and 3 servo motors. The integrated driver in Duet3D mini 5+ will not be able to drive NEMA 34. So I thought of using Duet 3 Expansion 3HC but that has only 3 drivers. I don't have any idea of how to expand the board for more drivers. What is the procedure for expanding it further?

Can I use DueX5 as an expansion for Duet3D mini 5+?
@dc42 can you give me any suggestions, Sir?

I am residing in India. I need to purchase Duet3d mini 5+ for our project. How can I purchase it in India?