Hi Mermaidman,
Sorry you haven’t heard back a little sooner (when there’s a new tank waiting, there’s no such thing as too soon, lol!).
It sounds like you’re setting up a freshwater paradise. Using the older filter media is great, just make sure your tank has fully cycled (which should be a cinch with the lush planting.). Another nice thing about planting so lushly in the lower strata is that oxygen starts to dip at about 19 inches of depth (around a standard 55’s measurements), so you’ll be doing yourself several favors—giving an extra O2 kick for bottom dwelling fish esp., for all fish in general, providing tons of cover for mid to bottom dwellers as well as helping expediate the turnover of disoloved organics.
In all it sounds like a perfect guppy tank with beautiful contrast, cover and tons of room! For maintaining all your greenery, had you considered otos:
http://www.badmanstropicalfish.com/profiles/profile76.html? They’re small, cheerful, docile and power-cleaners when it comes to keeping up with typical tank algae of both the brown and green vairieties and they’ll leave your guppy fry alone to grow into the colorful souls that they are. Takeshi Amano considers them one of the penultimate algae eaters and tank cleaners that no tank should be without. The rule of hand is to get one oto per 10 gallons, any more and there might not be enough supplemental algae for your otos (they do well on spirlulina tabs the rest of the time.). They are on the inconspicuous side, though. For a bit more of a show you could always add a few pieces of driftwood and a few bristlenose plecos:[http://www.badmanstropicalfish.com/profiles/profile117.html[/url]. Gentle, sweet, comics of the tank—they’re also champion algae eaters (although not as through as otos.). Imagine little catfish with anemones for noses. They come in a wide variety of patterns and colors so they don’t necessarily blend into the background (although they do love living on the bottom of the tank. The Panda Cory’s that you picked are a nice, showy schooling addition to the tank. Residing mostly at the mid-bottom, they like darting to the surface for air:[http://www.badmanstropicalfish.com/profiles/profile137.html/url]. Having had all 3 species I can tell you they’re all long-lived, beautiful, healthy souls that all make a community aquarium an instant attraction.
Here’s our profile on dwarf frogs:[http://www.badmanstropicalfish.com/profiles/profile99.html[/url]. They should make beautiful, peaceful additions to your tank.
Gouramis for the upper strata, colorful, peaceful, busy, bigger, flashy additions to the upper strata. Gouramis are related to bettas so they’re labyrinth breathers, requiring surface air:
http://www.badmanstropicalfish.com/profiles/profile99.html. Opaline gouramis come in a plethora of colorful patterns and are best for beginning gourami keepers. Your choice of rams is also excellent as their gorgeous colors and electric flashes from dynamically bright scales are like fireworks in the tank:[http://www.badmanstropicalfish.com/profiles/profile3.html/url]
Mollys, Swords, Endlers and Rasboras will all school along with your guppies as well as they’ll all livebearers, so they’ll share fry bearing opportunities together.
Essentially, it sounds like your primary choice is deciding/balancing quantities. Do you want to have a large smattering if different livebearers or would you like to focus on something like guppies and endlr’s which will hybridize the fry for more variety? That would be dynamic. Finding particular colors/patterns for particular species is easy on Aquabid:[http://www.aquabid.com/url]
The next question...once you have chosen your species and varietie would you like I put on stocking levels?