@mgiddings - No problem, that's what this place is for, so glad to help. If you want to go Amazonian, you're in luck as you have such a variety of plants available to you that will work. Most plants from rain-forests don't need bright light as in their natural habitat they usually grow under the cover of large tree canopies, making them excellent for vivariums. But always remember, whether its an jungle plant, a Tarantula or a Tree Boa, all things from rain forests needs superb aeration/ventilation, so keep that in mind when designing your setup. We can talk about some more ideas, but you must consider things like the budget, size, purpose and a bunch of other things before I can be of more help.
If it was me setting up a amazonian vivarium, I'd go for the upper part of Peru. At the right, and towards the back, use "rock" face, don't go too flat, and give it lots of depth. If you build your own background, include places where you can place plants. I'll have some substrate (I think peat & sifted Culterra potting soil would work great in a 50/50 ratio) also to the right. Use lots of rock to build up the land towards the background, and fill pockets with the substrate. To the left of the vivarium I'll have some flowing water (use a aquarium powerhead of adequate size, and use the attachment that sucks in oxygen into the water, as mountain streams are very oxygen rich) resembling the halved-cross section of a shallow mountain stream.
On the river-bed side, use very small pebbles as substrate (http://www.bourgetbros.com/site-admin/i ... 0-%201.jpg <-- like these). It must be between 3mm and about 10mm for the general layout, but use plenty of larger ones of various sizes to add to the appeal. You can even have one or two very large (15-20cm) stones added somewhere in the mix, maybe breaking the water's surface, or even underneath waterline.
Plants that I would use (although not all indigenous to Peru itself) include things like Alocasia amazonica, Alocasia "black velvet" & "Black magic". You can use a multitude of bromeliads, of which the Neoregelia's are especially pretty. Upper Amazonian areas has lots of different bromeliads. Also Monstera deliciousa, Philodendron xanadu, scindapsus (nice jungle vine), various mosses, that sort of thing.
The pic I included has two colored rectangles in it. Each rectangle is a representation of what you are trying to achieve in your vivarium, just in a scaled down way.
Hope this helps you with your ideas.
@Phunk - Looks like a happy Boa you have there! Plants also make the vivarium smell fresh if the setup is done right. Natural plants is the way to go, but they do take a cr@p load of time to maintain usually.