I agree with David R, having a sump off to the side makes life much easier.
I have sumps under tanks, and 1 off to the side, that one is totally open makes maintenance a breeze. Access to pumps, media, heaters without contortion is fabulous. I also have the water cascading 4 ft thru fractionating bio-towers into the sump.

You may also want to design a water change system where waste water goes directly to the yard or garden.
I have it set up so I open a valve and instead of overflow going to the sump, it drains to the yard.

I can drain 300 gallons down 2" PVC in a few minutes, close the valve and fill tanks (watering and fertilizing the tomatoes at the same time).
The entire water change in less than 20 minutes, with little effort.
I have sumps under tanks, and 1 off to the side, that one is totally open makes maintenance a breeze. Access to pumps, media, heaters without contortion is fabulous. I also have the water cascading 4 ft thru fractionating bio-towers into the sump.

You may also want to design a water change system where waste water goes directly to the yard or garden.
I have it set up so I open a valve and instead of overflow going to the sump, it drains to the yard.

I can drain 300 gallons down 2" PVC in a few minutes, close the valve and fill tanks (watering and fertilizing the tomatoes at the same time).
The entire water change in less than 20 minutes, with little effort.