Gofish,
If you are thinking of a trailer mount?
Take a look at my system.
It involves using a Backpack all the time. But the BP is mounted at back height so as it is grab n go........you DO NOT have to lift it on and off your back.
The trailer has a 250ltr flat tank and a 50ltr/min 12vlt transfer pump which fills the BP up in 20secs. I can, from an emty BP, be back on the job filled up in about 1 - 2 mins.
At home, in my garage, I have 3 x 210ltr water butts (joined with pipes at the bottom) and a 100gpd RO with small DI polisher running into them. This produces about 180ltr per 24 hr of 000 ppm water from a tap level of 250 -300ppm.
Now I have built my system around the Backpack. I firmly believe that with a mainly domestic round with varying access and varying windows that the backpack is so easy. As far as carrying it on my back.....I have no problems. Now I am 6,2" and 15 - 16 stone so well able to carry it. But I can appreciate if you are a 10 - 12 stone lanky stick insect! (No insult meant!) then the BP on yer back would be a problem.
Anyways, take a look and give me a call iff you want any more info
07815106363
David Salkeld