I have Butler Creek Stainless Steel folders (bead-blasted) and painted with Brownell's Dark Park Aluma-Hyde II epoxy paint.

The only quibble I have with the OEM BC folder is that it needs to have a sling swivel stud silver-brazed/ welded to the metal rod near the toe of the stock.  that way, one has a standard sling.  The rear QD sling loop can be attached to a similar OEM stud near the heel of the receiver when the stock is folded.

Aside from that issue, the BC stocks are much stronger than the similar Choate folders, because the stock of the BC stock is all metal, whereas the Choate folder has plastic components in the stock, and is so much weaker.  IOW, the metal stub coming from the folding point does NOT go all the way to the end of the Choate stock.   A member here verified this using a small, but powerful magnet.

Ruger mags are universally regarded as the best.  IIRC, Promags can be nearly as good, and the very latest generation of Tapco Intrafuze Mini mags are well-thought of.  Maybe some reading at the Mini forum at Perfectunion.com would be of help.