I may know some of your meanings but better to clarify before answering.
1. Assuming 2WD and talking rear and want a softer ride.
2. Assuming "arms" is swap to coil springs/trailing arms.
3. Don't know what a qa1 kit is.
4. The work and risk and fab will probably not be worth it. If you are looking for a better ride and don't care about original, look at air bags.
5. Maybe 60-62 GMC donor parts will work.
This is from 6066Club archives, 2004.... albeit 60-63 and may have no relevance,
"Well I did some research an found out that the chevy 60 to 72 springs would fit and I was able to get cargo coils which are a progressive weight spring. i ordered them at 1 oclock today and picked them up at 4 0clock and had them installed at 5:30 and only broke the 2 lower bolts. These cargo coils are nice because they didn't change my ride height,they still ride like a car when not loaded and when I put a load on them like my car trailer they can now handle it nicely. Also I took it for a ride around the block and these springs cut way down on the body roll that I was getting from the stock springs. All this for around $100.00 and an hours worth of work. It was well worth it. Anyone that is interested in these springs for your
60 to 63 GMC they are Moog Cargo coils part # mog cc603."
Believed to be member Al Smith