Yo Andyman - and the rest of you searching for the perfect solution for your veg and flower units... Have you guys seen SOG's version of the flower unit? Take a look as he has done a really good job of answering some of your questions with his beautiful design.when I plan on doing my flower units with the fence post, I am going to have them go in the side of the res rather than on top just to save about 6" or so. If I can find a long enough res I will run it underneith as long as its short enough. Im thinking one of them totes you slide under your bed and are about 5"-6" tall and long and kinda wide. This way I can have more vertical room for larger monsters.
https://www.rollitup.org/members/sog-albums-my-diagrams-picture42918-sog-aero-nft-v1-2.html
I know many of you know our StinkBud, SOG - for those of you who don't, check his action. He is quite the engineer and has published volumes of excellent info in his grow journal and room discussion.