[DaveK]

As you can see, just because a tank is small, it doesn't mean you will not have any problems.

Unless I had something very specific in mind, for a tank in the 12 14 gal range, my option would be for none of the above, and get something of a reasonable size. It need not be some giant 500 gal, or even 100, but it should be something large enough where, more or less standard, aquarium equipment would easily work.

My personal choice for a small tank would be in the 30-50 gal range. Small enough so it's easy to work, big enough so I have some stable water, big enough to keep a few things in.