Russ, in not many situation you will use more then 75' of hose or even less when more then 100.
I am using usually 50-75' of hose, very somethimes 100.
And van mounted does not mean you can not off load it.
It is just much faster work, more convinience to customer. All i do in their kitchen is to get few liters of warm water. No noise in their house and much more...
I am sicking when i need to remove the machine and need to employ the buckets.
Usually when you need to run more then 100' then the site is just not suitable for truck mount.