new server; win7 or win10, or win server

[rtarver]

Hello server guru's.

I've decided to upgrade my home server (does strictly home automation).  I currently have an Atom based unit, and am building an intel core i3 based unit.  The big question is OS.  I think I can still get win7 pro, but server is a bit pricey.  Any reason I shouldn't get win7?  I'm getting a gen6 i3, which apparently means there's less support for drivers or some such compatibility that's hard to ferret out on the web.  MS and Intel being who they are.

I'm thinking win7 and ride that until MS gets off their win10 kick.  But maybe I'm dreaming.

What would you guys do?  I find a number of sites offering download of server for a couple hundred bucks, but they make me a little nervous.

Thanks,

Russ