Everything Martial Arts Kitten said was helpful. If your friend is well affiliated within the industry and being a 2 time british thai boxing champion he must know of coaches he can take onboard, Or he must be coaching somewhere.
Location, demand for it, advertising your gym, kit suppliers, you will need bags, pads, a ring, mats and only after you've got a location i.e a big warehouse. Also since MAK has set up their own gym, I would be a little bit more appreciative of their help.
2 questions, whats your friends name? And why do they need you to post it for them?