I would get a Torch Coral. I have a bubble tip and only one of my clowns will sleep and nest in it. The other clown tries to get the clown who likes the nem to go to the torch. My bubble tip is not big enough.
I would not buy a nem if your tank is new or unless you have at least 4 watts per gal.
Clowns like to nest in everything. Fans, heaters, walls, rocks, sand, water. lol >.<