Not sure on the link for a conversion. If you have a standard upright fridge, check to see if the hinges on the door come off so that you can switch the swing of the door. If so, then there won't be any coolant lines running through the front door. You could drill right through there with no worries. If you're wanting to go through the sides, you'll have to do some more research.
2 Keg Basic Keg Kit, Dispenses two kegs at once! (Separate Check Valves!)
Brew Logic Dual Tap Draft System- with Reconditioned CO2 Tank :: Midwest Supplies Homebrewing and Winemaking Supplies
These seem to be the most popular 2-keg systems on the board at the moment. I ordered from kegconnection, but have been very unhappy with their customer service thus far. That aside....
One of these systems would allow you to start using your fridge, and you wouldn't have to convert it. Just open the door and use the picnic tap.
If you're wanting to convert, then you'll need faucets and shanks as well. Faucets will run about $30-40 for the new Perlicks I think. But you can find other kinds for cheaper.