I believe most video cards support independent resolutions (unless you want both screens to display the same thing..) if you want to extend desktop to both screens any card would work. Just attach one to tv out and another to a vga out (or DVI). You may have to buy adaptors for this to work.
I dont know if it can be different resolutions for displaying the screen. I was never able to get it to work at home. My monitor has to drop to hte lowest resolution to match my tv. I figured you wanted to extend your desktop. Perhaps someone else would know the answer.