Robert, I am looking at doing something similar with the yard wastes and chips we pick up in the landscaping business.
My current plan is to set up several long strips, (I am thinking 6 at the moment) and plow / disc the debris into one strip throughout the year. Then the next year moving on too the next strip, going back occasionally to turn the pile and keep it "working"
I am figuring on something like a 5 year plan going back to the original row. Then I could either sell the top-soil (always have trouble getting enough) or just keep building my property up, that sits too low anyway.
There are several commercial means of doing it, one I looked at a while back was like a big plastic cocoon that got fed like a sausage tube, supposed to turn it in about 30 days or somethng.
Not sure how practical or often, but could you afford to put old trailers out there where the folks could just load directly on them?
If I was pricing it, I would price by the yard, and maybe "mileage" or travel cost or some other pickup charge. Figure out yardage by having measuered sides on the trailer, much like buying mulch.
Good luck, I will be watching to learn, please share any insights you have.