here are the parts i need help on: (RAM, AND VIDEO CARD)
here is the ram that i was thinking of getting its 6gb ram which is just the right amount and its really cheap but im wondering if i can use 6gb ram in my i5 build cuz its tri channel RAM
Patriot Viper Tri Channel 6GB PC10666 DDR3 Memory - 1333MHz, 6144MB (3 x 2048), CL7 $139.97
Memory CAS Latency: 7-7-7-20 http://www.tigerdirect.ca/applications/SearchTools/item...
XFX Radeon HD 5770 Video Card - 1GB GDDR5, PCI-Express 2.0, CrossFireX Ready, Dual DVI, Display Port, HDMI
As far as I'm concerned this is a better PSU than the one you linked OCZ 700W ModXStream 80plus
Absolutely no point getting more than 4GB of RAM. Altho the set you linked is cheaper and faster than any of the DDR3 dual channel sets I saw on tigerdirect, so if I was you I'd buy that tri-channel set and just leave one stick out of the build. The only differences between dual and tri-channel kits is the number of sticks usually. So no compatibility issues.
If you are a casual gamer, then you don't need the 5870, altho I'd love to have it as a casual gamer, the next step up on the ATI ladder compared to the 5770 is the 4890, then 5850. But the 5770 is probably the one to go for and can just replace later if you need to. You can't crossfire with your chosen mobo.
If you're going to a mild overclock then that cooler should probably be fine, but I don't know enough about CPU coolers to make a suggestion on what would be better at that price point. You might also want to avoid a board that has a foxconn socket, in which case this EVGA board is a similar price and continues to support everything in your current build. This board can crossfire, altho I don't think the second slot is at a good speed (good speeds are x16 and x8).
If you do get a motherboard with a foxconn socket it would be prudent to do your overclock without increasing voltage too much.