i guess all the new X99 stuff would be the next step up. My video cards got discontinued 1 month after i bought them LOL - but that's the game we play
So X99, 4 GTX980's with water blocks on them, tons of DDR4 Ram and a processor that can process it all is what i WISH i had right now. But this 1.2 yr old "dinosaur" pc is still holding up good.
dont get 4 way sli... i know you have the money to buy 4way no problem but its just a waste of heat and power... the scaling issues and compatibility issues are horrible. your gonna get a TINY jump in frames, youd be better off going a 3way titan x set up, that 12gb ram will help you out, and with 3 titan x's you might actually be able to use the full 12gb of ram.
edit: i read the post about the guy on FB being a dumb ass, then i saw your video... for one, very nice set up. and im sure that guy on fb knows nothing about PCs... but i do have to mention that you were doing 130fps standing still looking at a wall, no action or explosions in view. not hating at all cause you system is better then mine for sure. just a thought that passed over