Anyway to get these to work with same sites? I tried multiple prefabs with no luck.

Not without some non-trivial enhancements to the plugin. SAM sites use the ContainerIOEntity class in the game code, and storage monitors only work on StorageContainer class. It may be technically possible to do, but the implementation would be ugly. I have other priorities so I won't have time to look more into it, but someone can submit a pull request on the GitHub repo if they want to take a crack at contributing the functionality.