Looks like you’ve got lots of softies already, so I’d look into lps and polyp types.
I’d try for a zoa garden, lots of euphilia, some brain types, an elegance, and shrooms. Maybe an acro if your up to the challenge.
And a nem for the clowns!

So, everything?
I do have some pulsing Xenia "planted" on the back wall, which I'm hoping/expecting to pretty much cover the entire thing, but other than that there's just a Sarchophyton on the left and a Kenya Tree just off-center, as far as softies go. I have a couple Zoa colonies started already, and have been looking at more - but for the shelves in particular I kind of feel like it's a waste of space for Zoas. I'd rather see them grow up that branching stone on the far right, for example - where I can't imagine getting anything else to thrive.
I recently had a very large blue carpet nem fail to acclimate (just before I rebuilt this layout), and I'm still a little traumatized by it - but I'm hoping to try again in a few months, placing it UNDER some of the shelves.
Shrooms I'm curious about, as I feel like most of the time when I see them in other tanks, they just look like brown crap taking up space that COULD go to something more colorful - but then I'm thinking ricordias might be nice? Stuff like that though tends to require lower light, and these shelves are sitting at a minimum of about 150 PAR, moving up to around 200, 250, and at the very top around 350 - 400... way too bright for any shrooms I know of.
I've already had one bird's nest completely die off on me (though to be fair, I think that's because I basically crumbled it when trying to relocate it), but I'm still eager to TRY to get some branching SPS going... Perhaps once my plating Monti starts looking happy...