If you, like me, live in a place where bananas are not grown widely because it’s to cold outside, i strongly advise you to buy one for inside. Dwarf cavendish is a good choice, but they do grow quite large. There is a super dwarf cavendish variety which will only reach 1.40 meters. If you like something different than the yellow fruit from the supermarket, you could also try Musa rubra/dwarf red which has red fruit and green-red leaves. If you live in banana country, you could also grow these of course, but i’d personally choose a higher growing variety.
I think it’s important that as many people in colder climates as possible start growing bananas, since tropical plantations are threatened by a fusarium fungus (Panama disease), which isn’t curable (yet, maybe GMO could change the game). By growing your own bananas, inside, in (very large) pots (or old bath or wheelie bin), you don’t risk loosing your plant.
Since all seedless bananas (which the three mentioned above are) are clones of one plant (via the suckers) you won’t help banana cultivation by introducing more gene-diversity. For that you’ll have to sow banana seeds and hope and pray and hope more that one of the resulting plants produces seedless fruits. But do you have space for that? No you don’t. Unless you try Musa velutina, which also is very small (and can be grown inside in not such a big pot). And decorative too, with pink flowers and fruits. Musa sikkimensis (darjeeling banana) is an option too, because it can handle temps as low as -20 C (since Himalayas). It does grow very large though, up to 5 meters in optimum conditions. Above ground part dies from frost if not protected, but roots and rhizomes stay alive. Fruits are full of seeds too, but supposedly taste a bit like watermelon. Experiments like those won’t likely produce triploid or more-ploid plants with seedless fruits I think. But by all means try of course, you never know. The darjeeling one is very decorative for your garden too, and who wouldn’t like to spend summer evenings, days and morning under a banana tree?
On a personal note, i’d love to build a house one day. On the south side i would have a glass wall and roof. There will only be a ground floor in that part of the house, and no flooring whatsoever, only dirt. In this high, very bright and warm spot, i could grow a banana tree full size. Building a tropical greenhouse is also possible of course, but it will be more expensive. And who wouldn’t love to spend winter evenings, days and mornings under a very large, productive banana tree?
If the planting hole is large enough, i could also grow papaya there, and monstera, coffee, tea, strawberry guava, tomato, cinnamon, pepper… And i’m sure cats will love it too.