i7 6700 or i7 9700k

Hello, can you please help me? I want to improve my pc to get more fps in games and maybe to play in bigger resolution than 1920x1080. The most played games are Guild wars 2 and World of tanks. What is a best way? Take my i7 6700K to delid and OC to high frequency than 4,5GHz or buy i7...