I picked up a used Sanyo 4912 for cheap ($30!) to convert into a kegerator. I've seen many tower conversions, but never a door mounted faucet. Would doing a door faucet eliminate the cooling issues that come along with a tower? I know adding a fan helps this, but equipment costs keep adding up and this would save money and makes sense.
The only downside i foresee is the need to set the fridge on something to make it a little higher, and having to deal with hoses when opening the door.