I use a bottle jack without problems and would certainly recommend them over scissor jacks. A trolly jack is good but to get the lift you realy need a small garage one which is bulky and heavey.
My jack is two ton capacity and only 6 inches high closed and opens to 12 inches at full extent it also has a screw out top to give a further 3 inches of lift.
One very good idea from Clive about driving onto the spare was one I'd not thought of. (nice one Clive). However I would recommend driving up a leveling ramp or piece of wood. You see, when one of my tyres burst the heat from the tyre was so great I could not touch the wheel without wearing those thick leather gardening gloves I happened to have in the car. So I wonder if the heat from the wheel might prematurely damage the spare.
One other thing I carry is a piece of 3/4 inch ply about a foot square, to put under the base of the jack on soft ground to stop sinkage.
One last thing that no one has thought of yet. Have a dry run at home, let your tyre down nearly flat and then use the jack you are going to keep with the van to change the wheel. You see, at home you can take your time, have a cuppa even. But out on the side of the road in the pouring rain at night you wnat to get going bl***y quick. Also you'll have the piece of mind that the plan actually works.
Steve LL