I HIGHLY recommend Birmingham Pistol Wholesale (BPW) on Hwy 11 in Trussville. Johnny Walker is the owner. I've bought and traded with him for many years and always found him to be honest and his prices competitive. But the MAIN reason I like to do business with him is the fact that he highly values his customers. Many (not all) gun shops around Birmingham are owned and operated by conceited jerks, and they employee conceited jerks, as well. I like feeling like I'm not considered just another "goob" wandering around the store.
Also, BPW has a huge variety of firearms, and if Johnny doesn't have it, he'll do his best to track it down for you.