If you're looking for used office cubicles in Orange County, you can try searching for office furniture companies in the area, such as OC Office Furniture. They should be able to provide you with a variety of options for office cubicles, as well as other office furniture. Other office furniture companies in Orange County include OC Desks, OC Modular and OC Office Solutions.
https://www.ocofficefurniture.com/new-desks-sets