Control Arms C10 vs C20?

[MidLifer]

OK, the last mechanical area I need to come up to speed in on my 1971 C10 is steering. PO at some point changed out the rear axle to a 14-bolt/8 lug and did the same with the front hubs. It now sits on 8-lug, 16" rims. I want to rebuild the steering and wanted to buy "loaded" control arms instead of pressing new ball joints and bushings into the old ones.

First of all, is there a difference in control arms between 1/2 ton and 3/4 ton trucks? Best I can tell, the parts the PO used came from a mid-70s truck (based on some part # searches I did). Also, when I look up C20 control arms, there is "standard duty" and "heavy duty" listed. How to tell which I have?

For that matter, was there a difference in other steering parts?

Lastly, I've read many posts that say that Moog is the best line of steering parts. Is there a board vendor who stocks/sells Moog? It seems hit or miss at NAPA and Rockauto. Hard to find everything (ball joints, tie rod ends, pitman/idler arms) from Moog.