The LFS where I buy most of my plants has just started getting it. Only thing is, it's $18.99 for a patch of it. I purchased one last week because I knew a couple of people who asked me to keep an eye out for it. They ended up each taking half a portion. If you want a whole patch or can find somebody to split it with, I'd be happy to purchase some next time I see it (hopefully with their next shipment Sunday or Monday) and send it off.
And just so you know, I do believe it's emersed culture. In size and form, they appear very similar to emersed Micranthemum sp. The submersed growth is usually a little longer and skinnier and the whole plant will take on a golden hue, from what I've seen. The specific name given this plant is Hemianthus callitrichoides v. 'Cuba' so there might be some slight variation between it and what people have actually been looking for.
If you're interested in having it shipped domestically, PM me. If you already have it taken care of, then great and good luck!
The plant is usually sold in its emersed form. The submersed form looks the same although the leaves might be slightly smaller. Color-wise, it all depends on the nutrient management. Healthy ones grow a lush green.