Sean
I must agree with musket, Light Railway Stores are my go to supplier, top quality and I doubt that they can be beaten on price. The thing is, of course, you are on the wrong side of The Pond. Have you no US suppliers that can help you? If push comes to shove, I'm sure a UK supplier would be happy to send to the US, the size and weight should be accommodated by letter post, so minimal extra cost.
Name and number plates from Custom Nameplate Studio
David