Kauai biotope Paludarium inspiration help

[scribnibbler]

When I went to kauai last summer I was inspired to do a Hawaiian paludarium. The more I researched I became even more interested in true biotope style aquascapes. BUT... besides plants the freshwater fish and inverts of hawaii are actually pretty boring so far.
My plans are a tall, almost to the ceiling vivarium with a chest level 55 gal water section. The back ground will be vines driftwood, root systems, and black lava rock creating an overhanging lip at the surface of the water and the background of the water covering the filter and CO2 needs. Lots of mosses, peacock moss, bromaliads, staghorn ferns like on kauai, a few vivarium safe flowers, and natural vines, maybe pothos. In the water I'll have anubias and amazon swords. Taro?

I was wondering if I could find a few new perspectives out there in your imaginations:
What kind of substrate? White sand? Black sand? Soil?
What fauna?
Any Hawaii 'looking' fish or inverts you think would enjoy a paludarium that opens in the front like a closet door above the water line? So... something that would dart out.

Any plant suggestions? Tech suggestions and sensors? Techn-geek stuffs, my bf's favorite.