If you need the uprights to be longer than 60", is there a way to extend them with another upright or do you have to install and hang from another rail?

The is an extender kit available that should be compatible with this brand. It includes two 30" standards and two connectors. Item #306208

Thank you for your inquiry. The vertical standard is not capable of withstanding the weight needed to hold shelves, etc. without hanging from the top rail which is either installed in studs or using anchors. Therefore, we recommend installing another top rail if you need to add an additional upright. Best, Product Support