I would suggest 2 smaller filters just because from my experience it is so much easier to maintain a clean and clear tank. I was able to find 2 Cascade 1000 canister filters at my local petsmart and paid about 100$ each and they work great on my 180 gal that has; 2 silver arrows, 2 jd, 3 tiger oscars, 3 frontosa, 1 lima shovelnose, 1 rtc , 1 peacock eel, 1 ornate birchir, 2 red belly pacu
( I know overstocked )
( I know overstocked )