$500-750 moderate gaming lots dling and watching avi format movies

APPROXIMATE PURCHASE DATE: end May early July BUDGET RANGE: $500-750 (im from canada)

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: gaming(i havent been gaming alot recently but id like to hav a comp able to game such as lieange 2), (Download alot of junk from internet such as avi files,etc)watching movies, surfing the internet

PARTS NOT REQUIRED: keyboard( not necessary but im looking for silicone keyboards which looks nice and easy to clean), mouse, monitor, speakers

PREFERRED WEBSITE(S) FOR PARTS: newegg.com, ncix.com, anywer good and secure

PARTS PREFERENCES: not sure what brand as lnog as its long lasting and good

OVERCLOCKING: Maybe (ive never builded a comp i might like to try but its prob not necessary)
SLI OR CROSSFIRE: Maybe

MONITOR RESOLUTION: 1680x1050 22'' samsung

ADDITIONAL COMMENTS: I would like a quiet PC since im running it most likely 24/7

AMD Phenom II X3 720
ASUS M4A78-E ATX 790GX
G.SKILL F2-8500CL5D-4GBPK PC2-8500 4GB 2X2GB DDR2-1066 CL5-5-5-15 240PIN Dual Channel Memory Kit
Radeon HD 4770

This was wat i was thinking as is the cheapest build ive though of dono what u guys think ?

dono if the motherboard is good ? theres alot other simular ones maybe cheaper but r they as good ?

video card what brand shud i go for as ther r mutiple?

and power supply and case i got no clue what to choose as it wont really matter just as long as its quiet n cheap its guud for me...

any ideas ?