955 can be tweaked into a 965 easily in Bios, there are plenty of decent air coolers that will allow you a good OC too.
I would stretch for a 5850, at your resolution the 5770 is living on borrowed time, even now there are plenty of games that cannot be maxed with it, and when using Direct X 11 the performance hit will be too hard for it
i've decided to go with the hd 5850. then i found this other motherboard http://www.newegg.com/Product/Product.aspx?Item=N82E16813157198&cm_re=usb_3.0-_-13-157-198-_-Product
it has almost all the features of my older one for just 89$
what is the difference perfomance wise? not considering that asrock is a value brand..
and then there is this one too..http://www.newegg.com/Product/Product.aspx?Item=N82E16813128438