I'm sorry I realise I should have explained better.
I don't do any cleaning. I bought a chain of stores which have historically rented out carpet cleaners as a sideline. However, these cleaners have seen better days and could do with replacement.
Now I know you professionals probably hate Rug Doctor and the like but lets say they don't take on new rental clients anymore (I think they are trying only to serve the likes of Sainsburys etc.) so I need machines which customers can use easily and which is commercial grade for longevity.
A Google around brings up many names, some known, such as Rug Doctor, Bissell, Karcher etc. and some not well known, at least to me.
Whichever unit we go for has to be a unit your average Joe can use so nothing overly complicated.