Need advice on mobo/GPU for my gaming build.

Hey everyone,

Here are the parts I have selected for my build thus far, everything is from NCIX.CA (Keep any suggestions to this website please as I would like to do all my shopping in 1 place):

CPU :
Intel Core i5 3570K Unlocked Quad Core Processor LGA1155 3.4GHZ Ivy Bridge 6MB Retail ($238.99)

CASE:
Antec 100 One Hundred Lite Mid-Tower ATX Gaming Case Black 3X5.25 6X3.5INT 1X2.5INT N ($47.98)

PSU:
Corsair Gaming Series CMPSU-600G 600W ATX Power Supply Active PFC 140MM Fan *3 Year W ($79.99)

MEMORY:
G.SKILL F3-10666CL7D-8GBRH Ripjaws PC3-10666 8GB 2X4GB DDR3-1333 CL7-7-7-21 1.5V ($55.84)

This build is exclusively for gaming, mainly multiplayer games, WoW, D3, GW2 and I would like to run everything on Max without any hiccups!

Being as is the my first ever build, and I intend to do it on my own, I was hoping for some assistance/verification that all parts are sound and compatible as well as some advice on a good mobo and GPU.

I was hoping to get a mobo that would have room for Crossfire/SLI even though I dont intend on using it right away (as the games I play right now dont support more then 1 GPU), I hope to in the future.

As for the GPU I was looking at either an Asus 7850 2gb or a GTX550ti, this is where I plan to invest the big bucks as it will have the most impact on my gaming experience.

My main concerns are:
- Compatible mobo
- Case doesn't need to look better then a cardboard box but a quite PC is a huge deal for me.
- Performance on high settings is of absolute necessity, this shouldn't be too difficult as the games I play aren't very demanding.

Current running total is $422.80, I would LIKE to keep it under $800.

Thank you for your time and I greatly appreciate everyones advice and input. If you would like to suggest a completely different system, be my guest, I am open to all suggestions.