How to Secure Funding for Large Land Deals Without Purchase Agreement?

Asking around 8 Millon I have an owner that has 15 plus properties over 2,000 acres around $3,500 an acre (some with buildings I don’t know how to comps farm buildings)
He is willing to sell off a few parcels at a time 87 acres to over 1000 acres.
He wants to know I am serious! and not waste his time. I do not have a purchase agreement. (No proof of funds)
How can I submit it to a deal funder and make sure they don’t go around me to steal the deal?
Does anyone know of a deal funder that does big deals?
Thanks Jeff

@jeffb I think you’re probably stuck if you can’t get a purchase agreement in place. Could try offering him earnest money in exchange for signing, but at this high level I would have a legally binding contract with attorney guidance in place instead of your regular purchase agreement that most people use so it holds up.

What happened? Did you get a signed contract?