For this to work you will need multiple versions of a card like this
http://www.newegg.com/Product/Product.aspx?Item=N82E16814195083
Each one of these cards supports up to 4 different monitors so to get 9 or 12 you will need 3 cards, 4 for 16 which would require an extended atx board.
if you want you could also go the nvidia quadro cards.
to display the entire desktop across all the screens leave the cards separate ie. do not put them in crossfire or sli
Hope this helps