wow, some nice stuff there.That is going to be very nice!
If you are open to suggestions on the Bonsai selection, might I throw in my $0.02? I think A Dwarf Hawaiian Umbrella (Schefflera?) with A root over rock style would look stellar! Or couple that tree with the humidity that you will have, and you should get some banyan looking aerial roots hanging down.
Ah, found it!
Visual aid: http://www.***ubonsai.com/
Good luck! ~~Kiyi