Edward
You want to use a GL-4 rated diff oil, this can be hard to find sometimes. 
You might have to order it from an autoparts store if not in stock, it is 
not very common-DONT let them tell you GL-5 is a newer version, it has 
nothing to do with new/old, but compatible metal materials. 
You should also be able to find a suction pump at any auto parts source 
too, but they are not usually under $10, more like $15. They don't last 
very long either  when they are cheap. (but long enough for the avearge 
DIY).
Dexron III is the same as Dexron now a days. You might want to add a stop 
leak to the PS system, when I changed my fluid last month to Mobil 1 ATF 
it developped a slight leak.
I have heard that LUCAS makes a great stop le