My DH cleans carpets they use industrial ones for big dirty areas but for homes they use a machine from machine mart (sorry you will need to google) it's like a Henry but it's just blue, honestly it's the best and it's only about £130 and you can clean fabric sofas to with it
I maybe a little late, but just got the following carpet cleaner last week Vax V 125A Carpet Cleaner and I must say it is great! It is easy to carry the motor speed is powerful and best of all it is great getting rid of those deep wine stains.
If you have not purchased a cleaner yet, I recommend you check it out
Thanks all, sorry for not coming back sooner, got busy with other things. I will have a look at all these - the other problem is going to be where to store it, we haven't got much space, so not completely decided to get one but very tempted!