couple of questions.
1) you have 2 sections in the midde. i assume the larger of the two will be your FW
refugium area. what is the other section for?
2) did you leave space and/or make some kind of bracket to account for the light that will be needed for your refugium? keeping in mind the WPG
section will only be relative to the amount of water in that one section of the sump, you can probably get away with a smaller fixture, but you will still need to mount it somewhere.
3) i see you have your plumbing running to the inside wall of the stand, and up to the tank. are you drilling the bottom of the tank and going with a durso style overflow?