I think I might really need about 4 gallons.

Well, I don't know what you're looking for, but here are some offerings:

A 6 inch rock covered with coralline, some halameda-like macro, palythoa, a couple of green speckled mushrooms and maybe some colt corals
or
A bright red yuma riccordia about an inch dia.
or
A 5 inch rock with a 4 inch green polyped sarcophyton and a colt and coralline
or
About 8 Ring of Fire zoas and 6 small green speckled mushrooms, unmounted, just on substrate.

Any of that sound interesting?

Jack