At the time I needed mine, NAPA or any of the FLAPS could not get the one that fit my truck. They may have them for it now. I think my new one originally came from Cardone. But I think you have to be a dealer to buy from them.
As to your question referring to the best way to go. I am by no means an expert on these old brakes. I just know I am very happy with re-working the original setup, and would trust it anywhere on the road.. I know brake systems on new cars and trucks are much more advanced now. I was trying to keep mine all original.
The only thing I might be concerned about, is I kept the original single reservoir master cylinder. But back in the day, they used millions of them. I know a dual would give added safety.
