If you don't have a sand bed the choice of those should be a mag, rock dwellar, providing you have sufficient light and tank params for one.
Not on your list but a BTA would also work, and much more forgiving.
Might also want to think about natural host matches depending on what clowns you plan to keep.
I would get the gig mainly because you don't have sand. But only if you can set up a qt and have cipro ready.
Sweeeeeet!!! You'll love the green one for sure! Do you have it in qt?