It is hard to say what everyone should take... everyone is different.

If your PN is resistant to improvement with supplements, I'd suspect a compression problem in the spine, or a hereditary PN.

The basic ones are B12 and Vit D. Once you get normal serum test results using these and still have PN...

Then
acetyl carnitine (starting at one gram a day in divided doses)
alpha lipoic acid 600mg a day or r-lipoic 100mg a day
benfotiamine 300mg a day

The first 2 target mitochondrial damage and the benfotiamine targets aldehyde metabolism (vit B1).

These are the back bone of the supplements.
A B-50mg a day, magnesium, zinc, are also important.
As as Fish oil (anti-inflammatory).

If you see relief using NSAIDs... then I'd go with anti-inflammatory things like the Fish oil, 3 a day, and grapeseed extract and or other antioxidants.

It might be worth going gluten free for several months, as this helps many also. Diet can be a big factor in PNs that don't resolve.