Look for a Farm Credit type bank or credit union. Typical banks only want home mortgages / construction loans so you probably need to avoid them. We've been looking for land for 2+ years now, just looking for the right amount, in the right "area" for the right price. Our lender is 10% down, they'll finance 90% for 10 years.
If you need a realtor make sure you have one that specialized in land purchases. Our lady is awesome. She pulls up stuff on her computer, sends it to us. Has maps of soil reports, topography, flood zones, city limits (which we are making sure we stay out of), school zones, etc. She'll find the comps for land purchases which you'll want to help determine the going rate. She can also look up nearby wells, with info on how deep they go to find water, etc.
You also need to verify any easements, but I'm sure you knew that. Lots of oil/gas pipelines out here.
Mineral rights out here in Oklahoma rarely come up with land (at least in the area we are looking at).
Also, consider setting up a trust to buy the land, just to remain a little anonymous (keeps your name off the county assessor).