A bigger van
Only kidding mate.
Decide if you are going portable, ie trolley, or tank supply in van.(Just to confuse things, you can do both).
If you go for a tank, best advice is get the biggest that will fit in you van(remember weight limit for your model. 1litre water - 1kg)
Use the "search" section on this forum put the item you're thinking about in there. Swat up. Most of your questions have already been answered, read it all.
Excellent reference.
Pj