I finished the plumbing and have the substrate and water in now. I didn't get a single creak out of the stand or floor as I filled it - this thing is solid! I'm currently working on the canopy so I should have some new pics soon.
As promised, here are some pics of my canopy and completed tank!
Pic 1) Underside of the canopy showing the Coralife electronic balast kits and four 4' T12 bulbs.
Pic 2) Showing off the doors. The entire canopy is made of cedar and is finished with polycrylic.
Pic 3) A peak downstairs. The 55G will be a planted refugium. That's an Eheim 2217 on the right.
Pic 4) A closeup of my substrate. It's 200 lbs quickrete playsand and 50 lbs quickrete gravel. The wood is Swahala driftwood from Drs Foster & Smith. It's not the best picture of the wood, but it looks really cool in person - very twisted, lots of holes, good range of colors from red, nearly black, and white; all in one piece.
Pic 5) The whole thing. I need to clean the front glass yet since there is a layer of sand dust on it (on the inside).