First post on this site but I have been reading content here for a while.
Regarding sump and overflow design you have to assume it will flood. I had SW reefs for a years and it was guaranteed it would flood at some point (usually when I was on a business trip). The cause was the U shaped overflow tubes that lost a siphon or blocked something. Consistent top water additions (read automatic) is critical with a sump based systems. Without it you will lose your pump in your sump but it is also part of the problem in floods.
I set out to design a FW tank that would use a sump design so I can have automatic water changes and a place to put stuff. Most importantly it had to have flood prevention built into the system.
As mentioned above the beananimal overflow design is the way to go. It has multiple redundancies and nothing mechanical to fail. Every other design I have used is either loud or fail prone. The beanaminal design is silent and creates no sloshing of water. The other major item I did in my sump setup is to install a high water drain (flood prevention and allow for automatic water changes).
I have included pictures below. It was a bit terrifying drilling the glass tank holes but slow and steady with a drill press will do it. My next tank I am going to put the box in the tank on the back side to make for a cleaner look.
The other major item installed is a tank controller (Digital Aquatics Reef Keeper Lite) it makes life with a tank enjoyable. It controls lights, pumps, water change pump, CO2 controller, top off water, dosing, etc. A cheaper DIY controller is Jarduino which is based on the Arduino platform which I am going to use on a second tank.