Due to zoning and land use restrictions, you will not find any land where you can put just an RV (or 2) to live in for longer than 72 hours in any of the incorporated municipalities around Phoenix. You will be limited to only mobile or recreational vehicle parks. These parks can be nothing but lots for that purpose or with full amenities, but they will be zoned specifically for and only for mobile homes, park models or recreational vehicles.
Even looking in the county areas, they also have similar restrictions the closer you get to developed areas; often with a zoning permit that can be changed if needed. You can be in the country for years with just your RV on your own lot and suddenly a 1,000 town-home development breaks ground and the county tells you you can n longer keep just an RV on your lot.
To do what you want, you have to give yourself some space between the major metro areas of Tucson or Phoenix. The further you are from those metro urban centers, the less people care what you have on your land.