The clean construction I give credit to my friend Ken. He's the genius behind taking the insanity in my head and applying it to lumber. Granted, most of everything you see has been in my head for a long time. Assembly is where Ken is a priceless resource. And he works for beer, so cheap labor.
For decor, one of the things I'm most likely doing is buying a couple box lots of large/xl malaysian driftwood from aquaticeco.com. or some other source if I find one. I'll take 1/4"-1/2" nylon rods painted with krylon fusion brown to bolt the pieces together to form bigger root-like structures.
My friend with the 2600 gallon tanks uses artificial plants found at a craft store. They are big and look great in his tanks.