Mark,
If it were me, I would isolate the corals to one side of the tank, or pull them to a holding bin for a minute. The tricky thing about tall tanks, IMO, is that the scape will look empty if you do not utilize vertical space. That said, a shallow tank, for example, Matt, or Andrew, are able to limit live rock to small size pieces of live rock, or nothing... This allows them to be able to use the bottom of the tank and still grow acros effectively. I am somewhere in between, but must admit, trying to fill 24" height to make the tank "not" look empty is sort of a challenge. If you tank is taller, let's say 30", I would utilize columns, if your tank is 48" across, two should suffice, 60" or 72", you may want to make 3... That or a pyramid type structure to utilize height at the peak may look cool too, then leave maybe 12" open space on either side. So maybe build your structure up to12" from the water surface in the middle, then cascade it down on either side. As you drop your structure on either side, you can make caves, dips, shelves, utilize pieces of branch sticking out to plug corals on, it is really endless. Once you have completed your structure, the place each coral based on color, growth pattern, your show corals sort of facing full front if you will. This way you can consider where each colony is to be glued or epoxied down. I would do the frags after, then finally place your non sps corals, probably down near the bottom. I know you know this, but when water is spilling, towels are going from dry to wet, the water is splashing all over the front of the tank, your pants and shirt is wet, and you start to get frustrated, then I think that is when we lose our artistic potential. At this point with me, I am usually like screw it, and settle for something less than what I envisioned. Please take my comments or thoughts with a grain of salt, I think no matter what... This is going to be a good experience, and I am certain that you will be glad you went through all the hard work, trust me, I have been going through it since November, I feel like my tank is finally where I want it, and just relaxing and watching my corals do their thing
Cheer Mark, stay warm, heck, it is in the 40's in FL, that is downright cold for us, lol...