Buy begonia 'non stop' tubers

[redser]

Hi, I'm wondering can anyone recommend where I could buy non stop tubers online? I have about 40 tuberous plants on the go that I raised from store bought tubers earlier in the year. They are doing great, but are not 'non stop' begonias. I'm not sure what they are exactly, they were simply described by the colour of the flower.
But I did buy 4 non stop 'plants' and they are amazing! Much more compact and the flowers much more numerous. So next year I would like to fill my beds and baskets with these.
So can you help?
Thanks!