Semi Budget PC Build help(64bit windows 7)?

OK so here is my question..i built my first computer. sort of it was more i bought my friends and updated the video card n hard drive. so i didnt really have to worry to much about compatibility. Im looking to build my next pc as going though any website will cost me 5x more then it should just for them to put it all together..anyway i will most likely but each piece 1 at a time and im looking to spend no more then 600-700 dollars. here is what im kinda looking at

windows 7 64bit

4-6gb ram(maybe 8 if i can afford it)

Quad core processor(or w.e you think is best)

dual video card(if i can afford it)

idc about sound card

case with fan

and w.e power supply im gonna need

motherboard: um idk something SLI i guess lol

i dont need a dvd drive or hard drive as i have a blue ray dvd drive in my old computer and 300gb hard drive which for me is more then enough to install a few games which is really all this rig is for

not sure if u can make what i want with 600-700 dollars so if u need to do what u think is best to make it fit that.. i know im asking for ALOT but i really wanna make sure that everything will fit together.

please reply with links to each of the items if you can.

Thank you Yahoo Answer people :D