What don't you like about 10?
Windows 7 is no longer being supported; security updates and OS updates. There's nothing wrong with windows 8/8.1. If you like that tablet look and feel. You can make it look and feel like windows 7 with Classic Shell/Open Shell or from Stardock Start 8. I've used both and prefer Start 8 but is's $4.99. I liked it way better then Classic Shell...I did end up buying it.
That said....I would recommend Windows 10 over Windows 8.