ATI AMD XFX Radeon HD 6870 Graphics card work on mac pro 2,1

hi All

i have a Mac Pro 2,1 (mid 2007 ) and i have Nividia 7300 display card . but i need Cards for 4 Displays on res 1920x1080 for each 27" display

and i think to buy the

ATI AMD XFX Radeon HD 6870

this will work? without any problems ?

my system is Snow leopard 10.6.8

thanks

Karem