Jumping from 2133MHz to 2666MHz isn't worth the money and effort, recommend you to go at least 3000MHz or more for a more significant improvements over memory speed.

Change the PSU, the PSU you listed is overpriced and not worth our money too due to lower grade of internal components compared to other same price PSU.

As for the GPU, only get Asus/Gigabyte/MSI/EVGA if and only if your budget allows and no compromise to other parts.

And I see you picked a 850W PSU, going for SLI setup in the future? I am going to include a SLI ready PSU now just in case you need it, if no plan on SLI, then you can choose 600W - 650W (save money).

Intel Core i7 6700K - RM 1599
Asus Z170 Pro Gaming - RM 719
Corsair Vengeance LPX 16GB (8GB x 2) DDR4 3000MHz RAM - RM 630
Asus GTX980Ti 6GB GDDR5 Strix - RM 3559
Corsair Force LE 240GB SSD - RM 369
WD Blue 1TB HDD - RM 215
Corsair RM850i - RM 738
Corsair Hydro H115i - RM 583
NZXT Noctis 450 - RM 619

Total: RM 9031 (ETech price inclusive of GST)