Mr. Rawles;
The Ozark Mountains and the Ouachita Mountains are part of a very old series of mountains that runs from the Mississippi drainage to the Red River. This formation has been worn down to its present height by erosion and was more recently split by the Arkansas river. In addition to the generous growing season and precipitation you mentioned, many parts of this area have recoverable natural gas deposits and in is common for farms along the Arkansas river to have gas well heads. In addition to a monthly payment, many of these farms also enjoy free natural gas for domestic use.
The Ozark and Ouachita Mountains extend north into Missouri, west into Oklahoma, and as far south as the Texas border. While there are many nice areas in Arkansas, you might want to compare the taxes and regulations in all four of the states in this area. The cities of Fayetteville, Arkansas and Springfield, Missouri are rapidly growing in population but land located even 20 miles away from these urban areas and their associated highway corridors would be reasonable locations.
Finding undeveloped land in not hard as you are discovering, finding land with good water (natural gas often adds a sulfur smell) and deep tillable soil requires a little more investigation and testing. The agricultural extension service from University of Arkansas, Fayetteville, and Oklahoma State University, Stillwater have great web sites and a local office in every county seat [in their respective states]. They can help with soil and water sample testing as can the local well driller.
One of the very best features about this area is its reputation as a low cost retirement haven for hunters and fishermen. Since most folks in the area live close to the land and survive during normal times in a more or less self sufficient manner, building a survival retreat/retirement home will not make you an obvious target. In some counties, over 30% of the population is composed of retirees. Hiding in plain sight is an effective form of OPSEC. – C.H.