i would just leave the default asus block and just use the EK VRM block.
cooling that part will not have any impact and would be marginally.
on m6e however the PLX does get hot when u use it.
i guess the cost of a hero+ek block = m6f.
i7 4790k@4.7ghz 1.28v||Asus Maximus VI Extreme||Zotac GTX Titan X Sli||Corsair Dominator Platinum 2400mhz 4x8gb 10-12-12-31-1T||Corsair Neutron GTX 240gb x 2 + Crucial MX100 512gb x 2||Creative Soundblaster Zx||WD Black 2tb & 2x1tb||Ek Supremacy Nickel Acetal+EK M6e Nickel Acetal+EK Titan X Nickel Acetal + Ek Red Backplate+Ek Dual D5 Top & 150 X3 Res+HWLABS GTX Nemesis 560+280+6xNoctua Redux 1500rpm||Corsair AX1200+Corsair Red Sleeves||Silverstone Temjin 11