then I advise to try and save some more as a single 5770 is really going to struggle with 2 monitors for gaming I should think...
What res are your screens?
For best value for money atm I'd get:Powercolor ATI Radeon HD 5850 "Dirt2 Edition"
damn good value for money with the game too - though I am not such a fan of Powercolor (think they have gotten better over the years?)
which should be able to run 2 screens ok