any way to push out clients to linux hosts from the Avamar server?
Do you mean pushing installation to client host? If yes, I think the problem is most of linux hosts don't have the centralized management. That means you cannot have a way to distribute the software.
However if you can write a script to transfer the RPM to Linux hosts and run the rpm command remotely. It could be a way to install Avamar client on many servers.