I love those dimensions, truly jealous. I'm always wishing my 75P had another 6" of length. This will definitely be the tank I buy when my 75P is too old to use, and it's definitely getting there... 6 years of use and 7 scapes, it's seen better days. If for some reason I can afford it by then, a 120H would take precedent over the 90P, but I'd much rather a 90P over a 120P.
I like the scape but it would definitely benefit from more substrate, more height and depth would really impact it in a great way. Would you have to order more or do you have a LFS you could take a visit to?
Goos stuff, cheers mate.
EDIT: I'm disappointed in you styx, where's the other LED pendant?!