And which ones to avoid?
I have yet to see a Pietta (my preference so far) based on the good luck I’ve had with them on other models.
I have started my hunt for a Walker.
Not in a hurry. I need to learn more.
AR, only current maker of Walker replicas is Uberti. Pietta has not made a Dragoon or Walker replica ever to my knowledge.
Armi San Marco made them until they went belly-up in the 1990s. The general consensus is the older ASMs were higher quality than the later models which have oft times been criticized for "soft internals", though I've not seen this myself.
Personally, I prefer the older ASM Walkers over Uberti due to (IMHO) better case color hardening (CCH), nicer bluing overall, extremely good wood-to-metal fit, and they lack the shiny red Uberti grips which I don't really care for. Many of them carry the proper Sam Colt address on the top of the barrel whereas the Uberti won't. Of course, any Uberti is going to have the infamous short arbor issue, but many of the ASM guns do as well. Bottom line is, if you want a NEW Walker, or Walker kit, it's gonna be Uberti. If you are willing to search on the auction sites and bide your time, some of the other makes can be found but not for a whole lot less these days, unfortunately. No doubt there were probably others that made Walker replicas as well, but I'm not familiar with them.
Hope this helps.