Which b vitamins and in what size should I take for non-diabetic peripheral neuropathy?

Depends on the cause. Neuropathy is a condition resulting from abnormal nerve function. Neuropathy can be due to certain vitamin deficiencies, nerve damage due to trauma, alcohol consumption, radiation, side effects of certain medications, or due to certain medical conditions such as diabetes. Treatment varies depending on the cause of the problem. Have it evaluated and appropriately treated.
B6 . The medical literature indicates that vitamin b6 deficiency leads to peripheral neuropathy; therefore i recommend 100mg per day of b6 in the form of 5-pyridoxal phosphate. If you can get this by intramuscular or IV injection even better because it guarantees 100% bioavailability to the cells. http://www.a4m.com/las-vegas-2012-the-nuts-and-bolts-of-nutritional-iv-therapy.html.
See below. Peripheral neuropathies vary in causation, but we can theoretically get guidance from our experiences in diabetes. A medical food metanx has been shown to increase small fibre density in diabetic nerves. This combination of vitamins b-6, b-12, and folate, (folic acid) is biologically activated, and may be more beneficial than standard otc vitamins. Talk to your neurologist about getting samples, vouchers.