So you are getting SS shelves, but they do not come with any kind of brackets to hang them? That seems a bit strange.

The bracket-and-standard system is pretty durable and flexible. The standards can be bought in various lengths and finishes, and the brackets as well. You hang the metal standard on the wall by screwing it into a stud, and put brackets wherever you want. Easy to adjust the shelf locations by moving the brackets. I'm not sure how rustproof they are, if you get the standard steel ones to match your SS shelves they may not be in very humid environments. You could always paint them first.

The biggest driver on the supports is how much weight you want the shelf to hold.

The higher the weight the clunkier looking the brackets get.

Knape & Vogt is n old line shelf standard company, with a various weight ratings and finishes.

They may look familiar because they are used in many retail displays.