Considering upgrade vs. overhaul

Hey guys,

I've got a couple questions and concerns I'm hoping some of you could shed some light for me. In 2014 a buddy helped me pick out and assemble a gaming comp, I'm not ultra tech savvy. Budget was about 700 bucks. It's getting to the point where I am considering upgrading components in my computer.

My concern is that my CPU is LGA 1155 and it seems that most newer CPUs are 1151 it makes me think that if I want to upgrade my CPU I would need to upgrade my motherboard. would i then need to get a new copy of Windows is that all necessary? The comp is used almost exclusively for gaming. I'm planning on potentially making some purchases come black Friday.

Current build is

MoBo ASUS|P8Z77-V LK Z77 LGA1155 R

EVGA 1060 mini 3G

CPU INTEL|CORE I5 3350P 3.1G 6M R

8x2g ram

Wonder what upgrade would give the most bang for the buck, or if more than a single upgrade is warranted at this point