Tiger (Server) in a virtual machine may be an option, if Classic support won´t be needed.
Leopard my offer better integration as X86 VM and it has Rosetta PPC emulation too, just as Snow Leopard.
While Tiger and Tiger Server work fine in an X86 VM, Leopard and Leopard Server have processor dependencies that can cause issues running in a VM on modern hardware. They'll run on a Core 2 Duo or older, but not on Haswell, Broadwell or Kaby Lake architectures, for instance. Leopard is also significantly slower performance-wise than Tiger in VMs where it does run, as it leans heavily on offloading graphics tasks to the GPU, which VMs don't tend to handle that well.