Ok. I liked the Camco EVO from Amazon. I replicated it at Menards with the following parts:
Omni Filter Whole House Filter
DuPont Carbon Wrap Filter
Misc Hardware to adapt to a garden hose
I bolted it to a piece of a 2x4 and used some nylon rope to tie it to the wheel to keep it off the ground. Bought a few plastic quick disconnects to make for a quick hookup.
Total cost = $45. I could have bought the Camco and paid the shipping and not have to worry about putting it together but it was a fun afternoon project and I can buy the filters at Menards/Home Depot/Lowes and not have to worry about spending the extra money on shipping.