.Decide what tank you want first then chose your van.
If its 400 to 500 ltr tank then a pug expert, but you dont have a lot of spare room.
I wanted a 800ltr tank, I have set the van up for two people working. The tank suits us fine we have not run out of water yet on a days work in 6 months,though it as gone very low at times.
I have a fiat ducato,which was brand new and cost me about £9500.00 incl VAT.
It has abs brakes,RCL, 3 year warranty. A lined steel bulkhead and a 1145kg carrying capacity. I can carry 8 poles in the van and I have loads of room. Heres a pic.