perhaps a video card to handle all the connections and doing it how I previously stated? or is there some sort of switch I can use to allow sound as well, because I need it to have sound sent to each TV along with a projection unit that I forgot to mention above
You didn't answer the most important question, Desktop/Laptop?
Well for desktop the solution would be to have at least 2 cards with 2 outputs, depending on the number already existing, you might need to ad 1 or 2 dual-output cards. You essentially need 4 discrete output, all of which can be controlled by windows, but you can't just use a splitter or repeater if it needs to be separate windows.
Something which works for both desktop and notebook you could add USB display port replicator like this; http://www.futureshop.ca/catalog/proddetail.asp?logon=&...
Just be sure your model supports an input resolution your LCD supports (most 1280x720 /1355/768 LCD TVs will take both a 1024x768 input and 1280x1024 PC input [as well as the TV standard 1280x720P)]
We bought 4 when they were on sale for $24.99. They are finicky to setup, but once working are great to add another 2D display, that renders mostly via CPU.
There are many makers out there so look for your local guys and I've used a few for multi-monitor apps here at work with them and they seem to work fine for the people we got them for to extend their laptops on the road (when in office, just connect to their docking station and same thing).
However is it is a desktop then you should be able to add a cheap second or third card and drive the extra monitors on that, and that would usually be cheaper than those USB solutions, which do suffer a bit of lag.
Now one thing, this is not running 4 desktops, that's a more complicated fish requiring specialized software. This is only for 4 separate windows, essentially extending your desktop (mirroring being easier than that [you could've used a splitter, but likely cheaper to just get more cards]).