You guys are looking at the corals wrong- esp the white one...
The orange one is Scleronephthya. It's similar to Dendro, but seems to be slightly easier to keep in an aquarium. Slightly. Best left for a dedicated NPS tank.
The white one is a partially inflated Sea Pen that is being viewed from an odd angle. It's actually a soft coral that buries a muscular foot into soft substrate and can move itself around. They can contract down far, then blow up to be Huge corals- way bigger than you might expect when looking at a closed one. They're really cool animals from a physiological point of view, but also nonphotosynthetic. These are easier to keep than other NPS softies, though still a challenge. You would need a very deep substrate of super fine sand/mud, and will have to offer multiple feedings a day. These can take larger food particles than what a Dendro or Sclero would- rotifers, oyster eggs, even small Cyclopeeze or newly hatched brine can be snagged. This isn't to say its an Easy coral to keep, but not a bad one for someone moderately experienced with NPS.