No choice for both. I used 1g "squat" bowls for everyday housing. For breeding, 10g tanks, half full worked nicely. 1/2g flat sided bowls worked well for juveniles once they seperated.
I've bettas in both bowls and aquariums; while I prefer to keep them in an aquarium, most of the ones I've had in bowls or 2.5 gallon tanks seem happy enough. I only one which didn't like it and lept to his death early on.