Actually, AS, I grow exclusively edible seedless varieties. A couple of them happen to be quite ornamental-looking (particularly the Red Iholene, which has burgundy new growth), but I'm growing them for their fruit when it comes down to brass tacks.
Here's the scoop:
Bananas are divided up in a somewhat arbitrary manner - basically what are termed "edible" are the seedless hybrids, and what are termed "ornamental" are seeded species and hybrids.
This said, if you're willing to put up with zillions of tiny, hard seeds in the fruit, you can actually eat the fruits produced by the "ornamental" types; depending on their heritage, these fruits range from delectable (any of the Musa acuminata subspecies) to pleasant (Musa velutina and its ilk) to a bit bitter (Musa basjoo).
Musa velutina, the banana mentioned in the article above, is considered a "dwarf" size plant, since in potted culture it grows only to about 6 feet of pseudostem (and another 4-5 of leaves). It's also one of the easiest bananas to grow in containers.
The most gorgeous of the ornamentals are, in my book, Musa acuminata ssp zebrina 'Rojo' and Musa 'Bordelon' - the first for its foliage, and the second for its stunning flowers.
Now let's talk about the food bananas.
The "edible" varieties are almost all triploid or tetraploid (ie three sets of chromosomes or four sets) (with the Sucrier and Fe'I groups excluded) - which means they're sterile. This is the whole reason why there are no seeds in the fruit. Hence, even if unscrupulous sellers and traders of seeds promise you seeds with which to grow an edible dessert banana, it's only going to happen for 1 in about 5 or 6 million seeds. Selecting for that one freak mutant is how we have ended up with the bananas we eat today.
This said, many places carry pups - the vegetative offspring of edible type bananas. This is what you want if you're going after an edible type. Good dwarf types include 'Dwarf Red', 'Dwarf Orinoco', 'Dwarf Brazilian' and 'Dwarf Cavendish.' If I had to choose just one of these bananas, I'd be going for the 'Dwarf Red' because a) I love the fruits, which have red skins and a smooth, creamy vanilla pudding sort of flavour and texture, and b) the plant is very attractive, since it has a red stem and red petioles.
If you've got higher ceilings, you might even want to give some of the non-dwarf types a look. But watch out for anything labeled "Ensete" or even "Musa ensete" (which is totally wrong.) Ensete are the African cousins to bananas, and they're true giants. Ensete ventricosum, for example, is grown here as a boulevard tree since it can get up to 40 feet tall before blooming. They're gorgeous, but they're definitely outdoor plants! A friend of mine in Morris Plains NJ has an Ensete glaucum (snow banana) in his front yard, and it produces leaves the size of surfboards.
Sandy over at Northern Tropics usually has one or more of the dwarf types for sale, although she won't ship until the weather warms up a bit.
If you've got any other questions, please don't hesitate to ask!