O.K thanks for you help guys, it is appreciated.
After thinking about what has been said and the fact that i am only looking to start a small round due to the fact that my carpet cleaning business is always quite at the end of the month i think that wfp may not be the best option for me and perhaps traditional is the way to go as i'm only looking at domestics, cheaper to get into and not as much gear to lug around so i won't have to unload my carpet gear etc, i know i could get a trailer as has been suggested but storage / parking is a problem for me at the moment, i had actually considered this and thought it might be the best option.
Now i am looking to build a round of approx 65 - 75 houses to do over a week doing up to 15 houses a day, obviously traditional uses a lot less water, do those of you who still do traditional use customers water or carry your own, i'm thinking some customers will be out and no out door tap available so will at least need to carry some water, what would be sufficient to clean up to 15 houses?