Hi Andy,
You are right, landowners can be very wary of letting strangers on their land.
You will need water, storage area, access at all times and possibly electric if you plan to site a cold room and have some lighting. I would first approach a local stables, as you would have a ready made market there. Remember to sell your project in a way that will benefit the landowner. For example, your future customers might like to go ride a horse. You can offer to take the manure as part of the contract. look to pay around 300 per acre, extra for water ofc.
That being said, the site might look good, but the most important thing about siting a new project has to and allways will be the soil. Choosing a site based around soil structure and type will save you years of messing around.