I made one for the 180 reef tank I had.
A simple piece of black acrylic was used to create a triangular overflow chamber in a corner. Tank bottom was drilled in 3 places. One overflow return, one spray bar at back at floor, and one gentle jet from the chiller. Wet dry filter with sump.
The gas exchange was incredible so in a freshwater planted tank you are going to be running your CO2 at 3-4 bps just to keep up.
The plus of all your labor building this is that there are no exposed pipes anywhere. Heater is in the sump. Water surface is always clear. More tank for fish and plants.
For safety, get a low water cutoff switch for the external pumps so they don't run dry. External pumps do not transmit any heat to the water. Iwaki.
FX 5-6 biggy type canister filters are the alternative. They make retro fit overflows but, syphons have a way of either being too quick, too slow or quitting.
Mr50's, Killer Plants, Whiskey Pond