hey all just wondering whats the best card/s for around the $2/300 mark?

needs HDMI out

My PC is coupla yrs old

ASUS mobo PDL*** (cant remember)
2 Corsair Dominator 2048 sticks
Intel Core 2 Duo 3.6ghz
Big arse Zalman fan
400w power supply (im thinking ill need to go bigger)

its going to be a Racing Rig (iRacing, rFactor etc) its going to be hooked up to my Samsung LED HDTV (reason for HDMI)
im going to use the PS3 wireless surround headset (only works in stereo not virtual 7.1 on PC) for sound & talk so hoping
this will run games at good prettyness & framerate but just mainly hoping to upgrade card not much else. also would i be
better using 64bit or 32bit?

any other uprgades or tips welcome

smoke