We have a few workstations here running 16.04 LTS, but our only server is on CentOS. Is it reasonably possible to setup Canonical's Landscape on CentOS/RHEL?
The server package can be downloaded free of charge -- but is distributed only as a binary .deb installable under Ubuntu and is under a proprietary license. It's mostly all python, thus the source is visible and you can attempt to install it anywhere. That said, I would recommend against trying to install directly on RHEL, sounds painful.
For a small installation, have you considered just a VM? Landscape server should run fine in there and would give you a better idea of how things function.