+1 tank looks awesome and sump looks tricky. Generally what will you do when the skimmer breaks or the floss roller breaks or you want to temporarily float a fish down there and it gets loose or a pump plumbing needs to be toyed with ...Will be fun!
But from personal experience, I would want more head height above the sump
Looks a bit tight from here
How will you clean the skimmer cup?
Does look like a cool and very roomy sump, but looks like it might be difficult to work around when something goes wrong, without having to drain the entire sump.
Could you raise the stand a bit more and make the blocks under the sump shorter?