+1
Nothing wrong with asking for recommendations from trusted colleagues. We use Ornamental Post and Panel but their
sign systems are likely a bit larger than you are looking for. How many are they going to need? If more than 1, you could weld some up or have some welded up out of 1" square steel tubing. You can use the
sign brackets from OP&P (above) or you can get them from an architectural metals supplier like King Architectural Metals. You can get caps, finials, and all kinds of other stuff too, for fabricating your own
sign posts and brackets. Fun and profitable stuff if you have the machinery to do it yourself.