The micro is the purple variety, although the plants offered and linked above have been in a low maintenance/ lower light tank and are currently green for the most part. They'll change back to purple under the right conditions.
The vals can tame themselves to a shorter tank, but may still choke out smaller or average size tanks. Blade width approx 1/8-1/4".
The ones in the pic above are spanning a 36" counter top and some are hanging over, I have a few that are over 45". They reach the surface of my 24" high 65gl, crawl over the surface and curl back down into the tank when they reach the other side. I guess it all depends on the height of the tank and how long you leave an individual plant to grow.
I don't think cichlids will eat them, my buddy put some in his multi-species Lake Tanganyika tank and didn't have an issue. My angelfish likes to bite them in half once in a while to show dominance. If it's a case of occasional munching like that, these vals grow pretty fast in a high tech tank.
Sale update - all E. tenellus micro is sold. There are about 13 vals left for the price of 10.