Hi Simon,
I can recommend the sebo bs for carpets, henry for hard floors (have a sebo in van for work (carpets) and henry indoors as we have all hard floors at home).
Not sure about training courses where you live, if you're looking at adding carpet cleaning as an add on to existing business then prochem run good general courses. If you buy one of their machines new you normally get a training course for free.
All the best,
Jason.