Hi Geoff,
not sure what your budget is but I have a Karcher 801D (petrol with diesel burner), mobile unit.
Bought two last year (one in van, one as back up) but very reliable so no need for the second one. Used only for 15 minutes in all except for occasional start up to keep it running.
I use these machines as company I used to work for before going self employed used them to clean Tesco's nationwide around the country due to low maintenance and durability.
Around £4000-£5000 new but looking for £3500...(as new condition)
Also got accessories for it including whirlaway, lance, guns etc.
Give me a buzz if your interested
Adam
07714 424335