Ford 134a goes in everything except the engine; use a good diesel engine oil for that. Do a web search to find out the specs for 134a and see what you have locally is the same spec. 5 gallon buckets of oil cost a fortune to ship one at a time, so find out what is on the ground near you. Get some new filters at the same time, especially the engine, fuel, and maybe air and hydraulic. The hydraulic filter is a big mother and expensive, same for the air. But since it's a new to you, you probably should change everything.
And by everything, that's all the oil under pressure, power steering, hydraulics, trans, rear axle.