Need Advice on ~$1500 gaming machine.

Approximate Purchase Date: Early May 2012

Budget Range: $1000 - $1600

System Usage from Most to Least Important: Gaming at max settings.

Parts Not Required: keyboard, mouse.

Preferred Website(s) for Parts: Whatever is cheapest

Country: Australia

Parts Preferences: Best performance/cost ratio

Overclocking: Yes

SLI or Crossfire: Maybe

Additional Comments: Hi guys im new to building a gaming machine, iv read a few guides on the forums and watched quite a few vids on you-tube. I have a few questions


-Have i selected the correct Motherboard?
-Will i be able to Overclock?
-Is SLI or crossfire a better idea?
-Is my tower too big would a medium suffice?
-Do i need low profile ram?

Coolmaster HAF 932
http://www.amazon.com/Cooler-Master-Advanced-SuperSpeed...

Corsair 750-Watt
http://www.amazon.com/Corsair-Enthusiast-Certified-Comp...

Corsair Vengeance Blue 16 GB
http://www.amazon.com/Corsair-Vengeance-Channel-Memory-...

ASUS LGA 1155 - Z68 - PCIe 3.0 and UEFI BIOS Intel Z68 ATX DDR3 2200 LGA 1155 Motherboards P8Z68-V PRO/GEN3
http://www.amazon.com/ASUS-LGA-1155-Motherboards-P8Z68-...

Sapphire 11196-00-40G Radeon HD 7950 3GB
http://www.amazon.com/Sapphire-11196-00-40G-Radeon-PCI-...

Intel Core i5-2500K Processor
http://www.amazon.com/Intel-BX80623I52500K-Core-i5-2500...

Windows 7 Home Premium SP1 64bit (Full) System Builder DVD 1 Pack
http://www.amazon.com/Windows-Premium-64bit-System-Buil...

Samsung 830 - Series MZ-7PC128D/AM 128 GB 2.5 Inch SATA III MLC Internal SSD Desktop Kit with Norton Ghost 15
http://www.amazon.com/Samsung-830-MZ-7PC128D-Internal-D...

Seagate Barracuda 7200 500 GB SATA 6.0 Gb-s 16 MB Cache 3.5-Inch Internal Bare Drive ST500DM002
http://www.amazon.com/Seagate-Barracuda-3-5-Inch-Intern...

Cooler Master Hyper 212 Plus 120mm Sleeve CPU Cooler, RR-B10-212P-G1
http://www.amazon.com/Cooler-Master-Hyper-Sleeve-RR-B10...

Viewsonic VX2450WM-LED 24-Inch (23.6-Inch Vis) Widescreen LED Monitor with Full HD 1080p and Speakers - Black
http://www.amazon.com/Viewsonic-VX2450WM-LED-23-6-Inch-...

Asus 24xDVD±RW Serial ATA Internal OEM Drive DRW-24B1ST (Black)
http://www.amazon.com/Asus-24xDVD%C2%B1RW-Serial-Intern...