10# can be harder to store, often meaning you need to put it outside the fridge. This means drilling your fridge and potentially hitting a freon line if you are not careful. If that's not an issue and you've got the cash OR live out in the boonies, get a 10# tank. Your CO2 will last a very very long time, something like 30 1/2 bbl kegs I remember right.
A converted fridge is by far the best way to chill them. With that system you picked, you have picnic faucets, meaning you can open the fridge, pour a beer and close it. No need to modify the fridge with a tower or door faucet.
However, if you only drink seldomly with friends and like to finish a keg, a jockey box would also work quite well as long as you clean it afterwards. No need to keep the beer cold the entire time.