With 1900 x 600 resolution you definitely want a more powerful gaming video card than a Nvidia 9500GT. And even the 9600GT (now more than 2 years old) may not be the best choice.
And how much are you willing to spend on a new video card?
How much was that Radeon 4830? It's about a year and a half old video card.
Also, what kind of power supply does your computer have? If you're unsure - just list the make and model of your PC. More than anything else (besides maybe your budget) it will be the limiting factor on how powerful a video card you stick in your system.