Absolutely what lowendlinux says. Although I'm a fan of Virtual Machines for many users, if my wife had to have Windows, I would bootcamp windows and have it boot into it (potentially exclusively).
As far as server is concerned, I would personally view it as a local backup. Seems as though iTunes cloud might be your "host" for multimedia though. We have a mini that stores all TV Shows and Movie content for the ATV to pull from... Every once in awhile the kids pull from the mini as well. I imagine you want to have a machine with all your local photos stored, and pushed/pulled to the cloud. Depends on what system you prefer to use; we use Apple's Photo app, but you can pull this off just as well in Windows 10 environment (or 7 if you prefer).
We're lucky in the sense we're 100% windows free. Bootcamp will allow you to successfully make the use of the solid laptop you currently own, and with minimal effort (compared to selling, and buying a windows machine).
