If you are able to fabricate stuff, you might consider a redesign, as the standard round plow skids would likely dig into a rock surface. I made the skids shown for my tractor front mount snow blower. This design wouldn't work for your plow, but the basic idea might. going over rocks would need more of an upturned front end, like a ski. (Mine in the pic use a simple bevel on the UHMW PE plastic, and have no need to pivot.) You'd need to have a vertical pivot pin about 1/4 to 1/3 of the way back from the front, so the skids will pivot and turn to track in your direction of travel.
Note I'm using UHWM-PE as it won't damage or mark pavers, concrete etc. It wears even better than steel, but it more expensive. I'm sure you'd be able to use steel skids and simply weld on hard face rod to replace wear as needed.