Peugeot Partner 400L set up,

[Jellylegline]

Hi I'm Martin and I've just been made redundant after 40 years working in a factory. As I've worked a bit helping a friend out pure water window cleaning, in trying to get a little business going. I've got a few regular customers working from a Gardiner back pack system. I've got a reverse osmosis system in my garage. I've just brought a Peugeot Partner 2012 plate and would like to put a 400L flat baffle tank in it with 2 leisure batteries and a pump and controller. Any advice for a tank and set up would be much appreciated.