First off I would cross PCP off your list. In addition to actually being shown to be neurotoxic, it has a lengthy stay in your body (days) comapred to ketamine (hours).
They're entirely different animals.. opiates might disturb or help sleep, they cause a tolerance that comes with physical dependence, and have unparalleled pain "numbing" property when you still feel some of the pain, but it takes on a less significant meaning perhaps.
Something like ketamine, you would forget the pain even exists. But only for a very short while (30min-1hour per full dose). This has been useful for me, in the past, perhaps to take some multiple times over the course of an evening. When not overdone, it has the potential of giving you a mental "rest" in such a way that once it wears off you can have a nice sleep and wake up more refreshed than usual, capable of facing your sober day in a more comfortable state of mind. It's purely psychological though, and unless the pain is merely extremely uncomfortable and not debilitating, it will not work like this. Also, there's a high chance of psychological dependence when it's used in such a way.
A combined approach might be best. To attuneuate your opiate doses in the evening, and perhaps as a better substitute to alcohol or benzos, it can be magnificent as it tends to potentiate opiates.
Ketamine has also been researched for phantom limbs pain and I think there are some positive results with that.