You should be able to share a server for multiple dev tenants. I'm not certain the SCW will set up the additional tenant just the way you want, but that's a good place to start to build the tenant record and DB itself. After that's done double check your ConfigDB Tenants list and be sure you've got both STG tenants listed and classified as Staging Landscape type. I'd also double check the license manager and make sure you've got licenses assigned to both your real STG and your "reference" STG tenants.
A separate FQDN for each would also keep things nice and clean.
If you just need to play around and look how it is configured out of the box, why don't you install it locally on a VMware machine?