You are very welcome.
And yes, running the two boxes in parallel (at least for the time being) is not a bad idea at all.
As for licenses, there are a number of options here. You may be able to find an old Windows Home Server 2011 license for sale. The problem is that the WHS code is no longer getting updates (patches, OS support etc), so after the current version of Windows 10... you may start to have issues with it.
The underlying OS is still supported until 2020, though.
Alternatively, you could go for WIndows Server Essentials. Specifically Windows Server 2012R2 Essentials or Windows Server 2016 Essentials.
These OS's are the direct spiritual and code successors to Windows Home Server (they're literally based on the same code, just updated). However, they are NOT cheap, coming in at around $400 new. That said, Microsoft does offer a 180 day eval period of the software. That's ... six months. So you can definitely try it out and see if you like it.
Otherwise, Depending on what you need, a WIndows 10 Pro license would probably serve you just fine. And sites like We Got Served (no affiliation-ish, though it's where I grew my online presence) does have guides on how to set up Windows 10 as a server.
Microsoft MVP for Windows Home Server 2009-2012
Lead Moderator for We Got Served
Moderator for Home Server Show
This is my server
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