The memory comes into it if your running at higher resolutions 1920 x1080 would need the 1GB really, 1680x1050 would be a toss up depending on if you were playing demanding games and anything below would be fine with the 768mb card. Personally i would spring for the 1gb if you can afford it unless you are running at 900x1440 or there abouts.
As far as the cards go i would put the EVGA and ASUS cards together and go with price, although i have a personal preferance for the ASUS card .
that be nice if I had that sort of Jink to spend with. I found another realiable seller of the asus for 179.00
And yea newegg is all sold out....their card was going for the same price...... Have to wait till monday to transfer money to my net buying account.....only keep cash in there when I plan to buy something....