Memory for Asus Maximus V Extreme

Hey.

I'm going to upgrade my PC.

What I have now is the following:

Chassis: Cooler Master HAF 912 Plus.
CPU: Intel Core 2 Duo E8400 Wolfdale LGA775.
Cooling: Noctua NH-U9B.
Motherboard: Gigabyte EP45-DS4.
Memory: TWIN2X4096-6400C4DHX x 2 = 8GB.
Graphics Card: Gigabyte Radeon HD6990.
HDD: 2x portable USB 2.0, 4x SATA2 HDD, 1 Corsair Force 3 Series F120 120GB 2.5 ", 1 OCZ Vertex 3 SATA III 2.5".
PSU: Cooler Master Silent Pro 1000W.
OS: Windows 7 x64 Ultimate.
Monitors: Samsung SyncMaster P2770H & 55 "LG LED TV.

I will replace the cooling system, the CPU, the motherboard and the memory.

I've been thinking about the following:

CPU: 3770K Ivy
Motherboard: Asus Maximus V Extreme
Memory: G.Skill 4x8 2666mhz [TridentX] F3 2666C11Q-32GTXD
Cooling: Corsair H100 with 4 other fans controlled by the motherboard.

But I've read a little and memories are probably overkill for the moment when they are expensive and difficult to obtain.

Perhaps it would be better to buy 2x8 1600MHz memories now and wait for the price reduction of the 2666mhz memories and buy another water-cooling system instead?

Or will a H100 with 4 fans do it?

I'll try to build a system that is stable at 5.0GHz.

What do you think should I wait with memories and buy a better cooling system instead?

Which in that case?