Hi there
With a halide ANY softie will grow fast and fill up space pretty quickly
Have a look around the members tanks on here and see what catches your eye then just ask based on that, there are so so many to choose from that recomendation is not easy but any of the leather's make a good display, the toadstools (sarcophyton) get big and are a good place to start as do the pussey and colt corals, the cabbage coral (sinularia dura) is nice and grows well and is a flatter more plating type form.
The best way though is to have a look around and see what takes your fancy.
After my move in to my upgrade next weekend (fingers crossed) i may well have a cabbage that i can let you have for just the postage if you are interested.
Regards