Or money no object why not just get yourself a ppb system with a hot water webasto heater built in instead...Sorted 
Why buy a lada when you can drive a bmw so to speak. They both have four wheels but would you drive a lada out of choice? 
For pleasure. If you want to gold-plate your van and put wide wheels on it and make sure it's a top range transporter because "they're the coolest and everyone knows it" then fine.
But don't come on here and say it's better at cleaning windows with the implication it is a better business decision without being able to defend it.
The only good business reason to buy any turnkey system (IMO) is because you are so busy earning money and guiding your empire with your fleet of vans. Even then why buy something that is as useless as gold plated taps over stainless steel.
If your business is THAT big then you will be employing a manager/technician anyway (or you or one of the savvy chaps can do it part time) and they can build or manage the build for you of an excellent tailor made system to your exact specification.
E.g. Van 1. Has to have hot on demand for all the first cleans you do.
Vans 2, 3, Good solid cold water systems with provision for sliding in a hot boiler where necessary.
Van 4 + trailer Set up with GutterVac/Pressure washing
Nowhere does PPB come into the equation.