Hello and thank you for your inquiry.
That is quite an inheritance, LOL. With the odd shape and depth of the tank LED lighting options will be somewhat limited especially if corals are kept towards the bottom of the tank. I have linked a couple of possible options below that might work for you.
EcoTech Marine Radion Pro Gen3
AI Hydra 52
With these fixtures you would need a minimum of 2, some maybe 3-4. They will generally give you about a 2'x2' spread when mounted about 12" from the water surface.
I would suggest shooting us an email directly to email@example.com so if you have any questions about the individual fixtures we have an easier time replying back and forth. We could then discuss budget, mounting options and other controllers or add-ons that might be needed for these fixtures.
Marine Depot Customer Service