Have a local fab shop bid them. You might get a deal or you might find they are quite expensive until you are ready to buy 100+. They will CNC them and possibly waterjet cut them if you don't need the holes precision or tapped. Waterjet is very good and will likely save you some money.
Make sure you specify finish. you will need a fabrication quality drawing.
SS will be a bit more expensive but is not a problem for a professional to work with.
I have my own shop and make my own manually but don't need any work.
Jerry