I am guessing that the back to that is the cheap cardboard which is actually a good thing potentially as I wouldnt use it at all since you can stabilize the cabinet with some l brackets instead and have good access... If I were to use that I would:
Route an opening on the door and recess a Fire tablet for control of the apex.
Have the shelf if any in the middle and get some MDF from HD or such to build false back walls.
All equipment controllers mounted to the top false wall with cord grommets to pass through wires. A hole on the back of the shelf to pass to bottom area.
Fake wall on bottom to hold EB8s. 2 grommets around them to feed wires.
https://smile.amazon.com/UU-BUY-Bla...8&qid=1485196584&sr=8-2&keywords=cord+grommet
On back of false walls use finger rail to organize the wires
Have a neoprene cord sleve for the wires back into the tank area similar to this:
https://smile.amazon.com/gp/product...act_title_2?ie=UTF8&psc=1&smid=A2N7NRZ9X3BHHN
For the plus I would also have them all plugged in behind the false wall and use something like this to plug in for uniformity:
https://smile.amazon.com/gp/product...act_title_3?ie=UTF8&psc=1&smid=A3ACUPJ4C2HX16
And above all else label things on the EB8 and on the cords so no matter which side you are working on you will know what you are doing.
You could hinge the false walls as well for easier access