Like G-rat says. PSA or BCA, I have a few of both and have had great results with both. IMHO I wouldn’t go smaller then 10.5 on a pistol build if your planning on it being a 5.56/.223 pistol. If it’s a 300 blk, that’s an animal you’d have to ask someone knows. I’ve read but never owned or shoot so expert I am not.
If you mean Sanders Armory then I think they are in GA. I know they were a couple years ago when I bought a rifle upper from them. I have been very satisfied with it and it was a great price.