Really? 'Ultra mini?' After all the discussion concerning relativity of size, I had to laugh. Ultra-mini, for me, needs to be something around the size of a Schoenorchis fragrans.
Good luck with your new Cymbidium. I really look forward to seeing pictures of yours when it blooms as these orchids are really gorgeous. I have often been tempted to buy one of the smaller types that do not need a winter chill but I just have not the room with the other plants. I do really love seeing the pictures of them here and when our members bring them in to the meetings and show as they are spectacular, even the smaller ones.
Someone in our OS grows all of her Cymbidiums in full hydroponics (water reserve, air pumps, etc.) and uses the little clay balls as medium. I will have to ask her how she divides hers.