Note that Microsoft has announced that Skylake and newer processors WILL NOT BE SUPPORTED EXCEPT ON WINDOWS 10:
http://www.nationaldailypress.com/2016/01/17/4209/next-generation-processors-including-intels-kaby-lake-wont-be-supported-in-old-windows/
If you are looking to continue using Windows 7 and Windows 8.1 (all decent enough OS’s) and want the latest hardware, best to get a Haswell-E 6-core platform and run Windows 7 and 8.1 on that as long as possible.
DO NOT get a Skylake or newer CPU if you don’t want to run Windows 10.