My preference of course would be to buy it, not sure if he'll go for it, but that's my Plan A. Plan B is the long-term lease, with having the first right of refusal. The way I had planned was to propose a deal my uncle made with a landowner. If the renter makes substantial improvements(fencing, water systems, etc), the original value of those improvements would be deduced from the sale price.
For example, if I invest $10,000 in the next 5 years in fencing and such, and Mr. Landlord decides to sell in 12 years, obviously the property value will have increased due to my improvements, but also due to regional inflation. It would get too complex to try and work out inflated values of the improvements, so once a price for the property had been agreed upon, the original $10,000 in improvements would be deducted from said price. Simple, but fair I think. Of course there's the chance that we may not agree on a price, and the improvements will be a tough pill to swallow when he sells to someone else, but that's the risk.
Anyway, thanks for the responses. Was just curious what others had done.