I'm currently gathering some spare parts for my PSA Gen4 Glock lower AR9.  No problems so far with about 500 rds fired, but I want some spares just in case. I have 2 PSA tool steel firing pins, 2 ejectors, and a polymer magazine catch bought so far.  I need an extractor, firing pin spring, and a mag catch spring if its not the standard AR15 spring. I checked PSA's website and these parts are not listed. Any help with sources or info about these parts is appreciated.

I run a New Frontier billet lower (similar to yours) on a 16" USPSA PCC, and for about 2 1/2 years with a blow back bolt upper... kind of lost track to the number of rounds but over 8000 ... I had an OEM firing pin break at about 400, but replaced it with a Colt OEM pin, and rounded the strike end to allow the hammer to hit closer to the center line... and that was the extent of problems... for the last year I switched to a CMMG RDB which uses an AR firing pin, but had the extractor insert plug harden and cause some reliability problems, that I believe have been solved with a new extractor spring and no insert....