there is debate,as to this subject.
as far as i know,there is no dwarf form,only tiny plants,that are young,and will eventually grow full size
if it is in full sun indoors,it will flower,as i grew one in england,inside,and got blooms.

I've watched some very healthy BOPs that grow leaves less than 18 inches tall and produce flowers. The old leaves brown out and the news ones also grow only about 18 inches or so tall and then die out. They never get any bigger. The problem is the hummingbirds seem to ignore these because they never set seed. The nearby regular size Bops set seeds on occasion, but the "dwarfs" never do.

I bought some "dwarf" BOP seed. The seedlings are about 4 inches tall now so I won't know if I truly have dwarf plants for several years.

Here's a site for dwarf BOP seeds. The website is in Germany, but its not too hard to figure out how to order from it.

Here is a link that might be useful: German Strelitzia seed site

Thank you!

Indoor growing is not ideal. Air conditioning & other environmental factors are not good growing conditions. You might consider getting two  one for indoors & one for outdoors. Periodically rotate them so one is being refreshed with one from outdoor growing.