I purchased the jack pictured in this thread in the end:
http://www.fleetwood-owners-club.co.uk/forums/index.php?topic=197.0
It has LED lights for use at night (I like LED's ;-), and fits nicely between both wheels of my twin axle as it's low profile. The long handle doubles up as a breaker bar type wheelbrace, and can swivel through 360deg so the jack could be used sideways on if desired.