barnes will have most sheetmetal you need, they may have dom, but bryan will prolly have to order it, angle is more than likely in stock, as well as 1/4" plate.
I get everything I need from Barnes. Just make sure to you talk to Brian. He can order DOM, I think the cutoff is you need to order at least 100 feet, and lately Barnes has been the cheapest on everything.
Dillion is UBER high.
BMG is wilson, I have heard lately is cheap but my quotes have always been high.
Let me know if you ever need a hand, i'm 10 min's from Nashville.