which post are you referring to? The Matrix is already pre-overclocked.
Though you can overclock all cards to same level (That said some GPU's are better overclockers then others), no matter the GHz branding or pre-overclocks done.
I w notougl for the ghz edition from gigabyte as it has spme stability issues, the matrix platinum and kingpin are both drsigned for ln2 cooling in mind so the price premium is not worth it unless you want the bragging rights, and the kingpin is arguably the best version as it can oc past 2gz on ln2, but for air cooling id recommend thr evga classified or the inno3d dhs edition
Personally, I consider the EVGA GTX 780 Ti Classified ACX as one of the best GTX 780Ti models on the market right now. True, you can find other models for a lot cheaper but when it comes to quality and reliability, EVGA is top notch.