You don't need a "M" (business) Visa. You can get one if you want but you'll need a letter of invitation. You could do a "C" (crew) visa or "L" (tourist) Visa. The requirements for Visa's change all the time so check with your handler on what you'll need on your trip.
These may be of some help...
China Overflight and Landing Permits ? Part 1: Changes in Lead Times and Revisions | Universal® Operational Insight Blog
China Overflight and Landing Permits ? Part 2: Permit Considerations | Universal® Operational Insight Blog