I would go with windows 7 still has long term support most businesses etc are using it and windows 8 is a mess to me I run it in a VM issue free. You can download both isos online and run them without activating them for 30 days to see which you prefer.
I run Windows 8.1 Pro with Start 8. Used Windows 7 before and wouldn't look back for personal use. However, at work, I wouldn't take anything other than Wndows 7.
To answer your question. It may be safer to just got with 7 for now.
Since you don't mention your use there is no way to really make a recommendation. Do you even really need Windows?
Anyways, I'd just get Windows 8.1. It is the most recent version and the way Windows is heading. So you may as well get used to it sooner rather than later.
Getting Windows 7 is pointless. That's the past while Windows 8 is the foreseeable future.