Look up bean animal return
I have a 75gal cube, set up with this return and ultra silent and safe. Only possible downside is that your return needs to go up the back.
Briefly how it works, you'd need to get all the measurements. I have a 3/4" pipe with a strainer on it, it extends about 3/4 way up the overflow, this pipe has a valve on it under the tank. The larger hole in the overflow has a 1" pipe extending almost all the way up to the water level of the tank. You adjust the valve to bring the waterlevel in the ocerflow just slightly over the larger emergency overflow. This causes the smaller pipe to be a constant suction with no air noise. The larger pipe has just a trickle entering it-quiet also.