That PSU might work but you'd definitely be better of getting a new one. Get at least a 400w, something from FSP would be good, good PSUs and not expensive. If you have the money, get at least a 550wto 600w, you can always use it in another build. Before getting a video card put at least 1GB of RAM in that machine, this will do more than anything to speed up the machine. I wouldn't put much money into the video card give you won't be able to use it in a new build.