Computer Upgrade Questions

Lets say I'm on about a 600$ Budget and I want to upgrade my computer for a New MMO's / I also would like to Stream/Fraps gameplay

I have an AMD 970 3.5 / Radeon HD 6950 atm

I'm considering either upgrading to a AMD 8Core / Radeon HD 7970 or 7960 or Nvidia 670

or either upgrading to Intel 3770k and Intel Related Motherboard



If I wanted to upgrade my system for a MMO Which do you think I should do first, CPU/GPU Upgrade or CPU/Mobo Upgrade

Any help would be appreciated