In other words you want a video card w/ 2 DVI outputs and 1 HDMI output.
You wanna use adapters to plug two existing VGA monitors into one (dual) DVI video card. And you wanna plug your home theater screen into the HDMI output, of same card.
This is a card that drives 3 screens. You can move anything from the main screen to either of the other 2 screens, etc...you will see. It's confusing at first, but not difficult to master.
And so this depends on your motherboard.
Yes, you must go to the motherboard manufacturer, and find the list of compatible video cards.
Your card has 2 DVI outputs, and 1 HDMI output. The more expensive, the better.
Actually there are a huge range of prices, depending on your approved card list.
But generally spend more and get more.