Bod
The most important thing in wfp is your RO
Find out what you are buying!
In my opinion you should get the biggest/best one you can afford.
Otherwise you will find with 6 -12 months you will be upgrading it.
I have a pro300GPD (thats 300 gallons per day)
Fills my IBC in a day and a bit.
I use between 600-800 litres a day (two man team)
So it will be shed loads for your trolley but you can turn it off when not required
and when you upgrade to a van mount you will not have to fork out again