Can you put anything next to the tank? Like a small table with 2 canister filters, at a slightly lower level than the base of the tank? Otherwise several really powerful HOB filters would be my recommendation.
3-4 of these They are outstanding filters. I use them and will never again waste my time and money on the lesser filters on the market. I have had mainland filters running for years (Magnum, Penguin, Emperor) I have a Magnum canister that has been running for over ten years. Never once have any of them failed.