I followed the links provided and found they all led to CUT orchid sprays, not the plant. I started looking for orchid suppliers for Sonia, and it's odd --- I can't find any, no matter how prevalent the color and variety is - I did locate the following supplier that you might contact about a "Sonia" - it looks like they have it or one similar in their inventory -
Hawaii Floral Products - Welcome
Or maybe
Kalapana Tropicals
That particular dendrobium hybrid is grown by the TONS in Thailand - and there are suppliers advertising plants, but I don't know about required certificates, etc. for shipping from there.
I had to search google with keywords "dendrobium hawaii orchid plants" to get what I got - not an easy find.
According to another member in a previous thread, this is a Dendrobium phalaenopsis variety not a cross of the two; I am glad they caught and informed me of that.
Best of luck finding one you like - they offered a lot of different color variations on their websites.! You will probably have to go with a "looks-like a Sonia" plant.
Steve