Which video card should I buy for my desktop IBM Lennox PC to connect to my monitor and my 42" Samsung Plasma?

I am considering a VisionTek Radeon HD 3450 512 MB DDR2 HDMI w/ 5.1 surround video card. My PC has max output 310 (watts I believe). I want to run sound and video to my pc. Currently, I have a NVIDIA Quadro FX 540. It has a monitor port, DVI port, and a 12 hole port. Should I get the Radeon 3450, keep my 540, or look for something else? I do a little gaming (Battlefield 2142) and will watch movies off of my pc to my plasma. Any useful advice would be great.|||Keep your current card, or get an 8800GT. If you have the money, get the 8800.