I went with a chest freezer only because it easily holds 2 carboys, plus a few 1-gallon jugs. Depending on the fridge, you may have a hard time fitting two in there. If you only need it to hold one, then either would work, and the fridge-style would probably be easier to get beer into and out of.
At the time, I didn't have the desire or time to scour CL and find a good deal, and you can buy a basic freezer for under $200.