Converting from 2WD to 4WD

From Crankshaft Coalition Wiki

I have 1958 2wd chevrolet panel truck. I want to convert to 4wd as finding a 4wd version is very difficult. What are my options ie napco conversion ,frame ,chasis swap or other. some one who knows please fill me in im a rookie but have great friends with skills and tools willing to help and teach me.