The 5xxx are great cards. I wouldn't dip much lower than those on a new system. A 5770 will be great at 1280x1024
The 5xxx series cards have 2 Dual Link DVI-I slots right? My monitor only has one slot for the wire to go into. Do I need a new one or is there just one slot for the monitor and two cables for the graphics card?
1 x DisplayPort
2 x Dual Link DVI-I
1 x HDMI