@envy14tpe Nice build, no complaints at all. A good build indeed.
Anyways OP, you should try Windows 8.1. It is just like Windows 7 but a bit faster if you ignore all the metro stuff and other bull$#!t features. Other than that, the Windows 8.1 is a very good OS and it is newer so it would have support for longer.
Soon Windows 7 would meet the same fate as Windows XP. So, if possible then go for the Windows 8.1 and ignore the Metro stuff. It would last you longer.
I personally like Windows 8.1 more when compared with Windows 7, but the end choice is yours. You cannot go wrong with either of them.