FWIW I have a radeon 2600 XT and I am upgrading to a 5770 Juniper. It can be had for around 100 on the egg. As I recall back in the day the 2600 was like 200+ .
It would allow you to run 3 monitors. 450 watt PSU required for single card.
System Manufacturer/Model Number Custom build; parts from the Egg OS windows 7 Professional 64 Bit CPU I7-3930 Motherboard Asus P9X79 PRO Memory G.Skill 4X 4 GB DR3 240 pin 16GB total Graphics Card EVGA 670 Sound Card Energy Take 5, Sennheiser HD 205 phones, X-FI Monitor(s) Displays Hanns G 21.5" HH221 and Samsung 19" 940BW and Hannspree Screen Resolution 2X 1920X1080 and 1X 1440X900
Keyboard Logitech Wireless and backlit Mouse Logitech Rollerball PSU 1000 Watt XFX Pro Series Case Thermaltake Chaser Cooling Corsair H80 Hard Drives 3-- internal 250 GB WD; 1-- internal 1 TB Samsung ---plus 3 WD external HDs (sizes vary to 1.5 TB); Crucial M4 128GB SSD, 1 Pioneer BDR-207 Bluray writer;
and 1--LG Lightscribe DVD drive Other Info 79 " long desk from Ikea. Sauder 71 inch long "speaker" shelf.
Optical and analog outs to a Yamaha RX-V 650 driving Energy Take 5.1 speaker system. Technics TT. Realistic mixer. Senns cans.