Need some help first time going all out with a build.

[Heerox]

Budget: 1500 is my limit (if you guys can swap my list out for something cheaper that's cool too)
Resolution 1920 x 1080
Games / Settings Desired: I play quite a few games most notably Battlefield 3 (in the best way possible)
Any other intensive software or special things you do (Frequent video encoding, 3D modeling, etc): Strictly for gaming
Country: Canada
Parts that can be reused: I already have an i7 3770k which I plan to use in this
Do you need an OS? No
Do you need peripherals (e.g. monitor, mouse, keyboard, speakers, etc)? Not at all

COOLER MASTER HAF X RC-942-KKN1 Black Steel/ Plastic ATX Full Tower Computer Case
ASUS SABERTOOTH Z77 LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard
SAMSUNG 840 Series MZ-7TD120BW 2.5" 120GB SATA III Internal Solid State Drive (SSD)
EVGA 02G-P4-2678-KR GeForce GTX 670 FTW 2GB 256-bit GDDR5 PCI Express 3.0 x16 HDCP Ready SLI Support Video Card
CORSAIR Vengeance 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CMZ16GX3M4A1600C9
Noctua NH-D14 120mm & 140mm SSO CPU Cooler
Intel Core i7-3770K Ivy Bridge 3.5GHz (3.9GHz Turbo) LGA 1155 77W Quad-Core Desktop Processor Intel HD Graphics 4000 BX80637I73770K
CORSAIR Enthusiast Series TX850M 850W ATX12V v2.31 / EPS12V v2.92 80 PLUS BRONZE Certified Semi Modular High Performance Power Supply

I know I have chosen a large full tower, I wanted the room to grow and not have much difficulty, I want to be able to overclock going into the future on both the GPU and CPU. As well be able to SLI the Graphics card somewhere down the line. That being said I went with an 850 power supply but I am not sure if that's too much or if a 750 would be ok. Finally the SSD is solely because I don't know where I can find the 830 version in Canada. Thank you for the help in advance.

[Deleted]

Since you can't find a 830 I'd change it to this:

Storage: Crucial M4 128GB 2.5" Solid State Disk ($102.79 @ DirectCanada)
Total: $102.79
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2012-12-24 15:17 EST-0500)

I would change the case to a Corsair 650DW or Corsair 500R Black || Corsair 500R White

I'd suggest one of these modular Power Supplies, they all have enough power for SLI (all SeaSonic OEM):

Antec HCG-620M
Corsair HX650
SeaSonic M12II 620

If you're sticking with 16GB RAM get 2 x 8 and something low profile:

G.SKILL Sniper Gaming Series 16GB (2 x 8GB)