Z or new M visa?

Hi,
I have been in China for 4 years now helping my fathers company. It is a HK based company in Shenzhen. I have always got a multiple F business type each time either from HK or UK.
Now I am starting to set up my own business sending Chinese students abroad to study. I have a Chinese partner and we have set up and office now however everything is in his name and the company is in his name.
I am not getting paid a salary but am only working to commission so any students we send abroad I will make a percentage for that.
This does not seem to me like I am being employed with someone so would this fall under the new M business category or would I still need to apply for a work Z.
Bear in mind I have never had a work Z before and cannot afford to go back to england right now.
What is the new M and how long stay can you get with it?
Any advice or comments you have would be most appreciated!
Thanks