ok, i don't have time to read the whole thread.. but i have an idea for my 180. it's acrylic and it has no cutouts in the rear for HOB or anything else for that matter. so i think what i want to do is buy a tub that fits into the open part of the top and hangs down into the water. drill holes for water circulation, and put the plants in that, sticking out of the top of the tank. and make something to hang the lights above the plants.
of course, this may have to wait till i move, depending on what i find out about staying from the attorneys