best bang for your buck

So currently I have a Asus G11Cd with a i5-6400, My motherboard has a H110 Intel Chipset. I'm wondering if I can update to a more recent type of CPU and what would be the best bang for my buck. Also, would I have to buy a new cooler for my cpu? And quite possibly maybe a new PSU also as I don't...

http://pcpartpicker.com/p/pdjcjX Is it a descent computer build?

Hey everyone :) So I'm building a computer soon, and if the 800 series isn't out by the time i finally get to building/ordering, or if it's out of my price range, I'm thinking of going with a GTX 780. Now my question is, would it be worth it to spend the extra $100~ for the 6Gb version or...