These are my personal favourites for filtration, mainly used on marine systems bet are easily adapted to freshwater by different media
You have an overflow of some sort. Either an overflow box that goes over side of the tank, a weir that goes through the side (must be drilled so water goes through side) or have a weir that rather than being a triangle like the one through the side is like the juwel filter but goes through the bottom of the tank via a drilled hole.
The best option for you is the overflow box as you don’t need to drill the tank similar to this
The pipe (either through the glass or attached to the little pipe bit on the overflow box) then goes down below the tank to another tank below the display tank, this is your sump like one of these tanks in the stack but yours can be as big as you want.
This has sheets of glass to reduce and even out the flow rate; the pipe will let water in on the one side where you'd have your sponges to catch the muck.
You would put in the ceramic media or the bioballs in the baffles between the sponge and veggie as this is where the bacteria live.
The water then flows through the baffles and into the middle where you can have a veggie filter (marine its normally caulerpa, fresh water can be things like elodea or floating plants or anything else fast growing to remove nutrients thus reducing water changes a bit and inhibiting algae, you light the plants under here with a plant light.
You can put a fine filter floss (like a pond filter one) to catch bits of leaves to stop them getting in the pump, and to catch fine bits of stuff that are in the water to stop them getting into the tank.
At the end you put the pump to pump water back into the display tank via a pipe and you can use a spray bar between the surface and where the overflow cuts off to stop you over filling the sump if the pump cuts out and you don’t want to have a hole drilled in the pipe.
Or you could drill a hole (fair sized one) in the pipe in line with the water surface then you could have the outlet as far down as you want/need.
You’d want 6x the tank volume per hour going through the sump so you would have a 600 lph pump on a 100 litre tank.
You can then use the sump as your filter, to increase the water volume to make the tank more stable in its pH etc, to hide equipment like heaters etc in, to add medication to the tank, to put in bully/injured fish, to add carbon/nitrate/phosphate etc remover so you can easily remove it and some other purposes.
If I had the space then i'd have all my tanks on a sump system.