New Video Card, How much potential for more monitors?

So i have an Nvidia integrated card, a 6k series of some sort, and I just upgraded to an ATi Radeon 4850. It has two analog/digital DVI outputs and a single S-Video output.

Now considering that I have two VGA monitors hooked up to the card at the moment,

Could I dedicate the ATI card to one single display for gaming and use the integrated card as a surfing/mods/cheats display for my second monitor?

Also, how many monitors are potentially possible in this setup?

I can convert the S-Video to DVI, so could i run that for a monitor too? And where does the integrated card come into play with all this?

Thank you for your patience because I am new to graphics cards.

And thanks in advance for reading and/or helping out.

P.S. for the optimal setup for this, what is the best cost-effective way to go about it?