Hi Ged
A comprehensive list there. Dont know what you budget is but there is a few quid there.
HWE - get at least a 2 vac machine with a min of 135psi, preferably higher ie 400
A bonnet system may not be necessary straight off - depends if you going to target commercial with low profile. If not initially then you could save spending that money straight away. You will get a 2nd hand bonnet machine cheaply, but new pads cost a bit.
Whilst an aggitator like a Duo or Oreck may be good (I prefer a heavier machine like a Envirodri/Host) you could stick a brush on the bottom of a bonnet machine and use that. Or save money and buy a long handled carpet brush (you will need one anyway).
A good upholstery tool is needed.
A stair cleaning tool.
Advertising is going to need a good budget not only initially but for a good time after as well.
You will need public liability insurance. Lots of threads on this forum - do a search. Make sure you get "treatment risk" included, covers for the carpet/upholstery you working on. Best to have this, but you will need it if you want to join NCCA.
Glad to see you investing in training. NCCA is a good course - enjoy. Maybe you will get down to their Technical Day here in Warrington on 9th June. See another thread for more details.