hey dthyer, seems I missed welcoming you 4 posts ago. Ah well, welcome to AT Forums.
Typically most video cards these days have just an S-Video output. The cable that hooks up to that will then have a split giving you the option of S-Video or composite. Essentially the difference is that with S-Video chrominance and luminance information into two separate signals where with composite they're combine on the same wire. Which is good, cuz it gives you an easy and cheap option.
If your card comes without such a split adapter, simply go to Radio Shack and pick up an adapter. Costs $10 at my local store. Since the singals are similar it doesn't require a different video card, just an adapter to merge the wiring for you.
--Mc