Can 1 oscar stay in a 80 gallon tank with an aquaclear 110 hob or could the oscar stay in just a 55 gallon? Or could I have 1 JD in a 55?

A 55 gallon is the minimum tank size permanently for an adult Oscar entirely by itself, an 80 gallon would be much more suitable. The primary problem with 55 gallons is the fact that they're pretty slender and it is difficult for such a large fish to turn around comfortably.

The minimum tank size is not entirely ideal and you have to work much harder to keep your fish healthy (but it's not impossible), which is why it's always suggested to go above the minimum tank size.

Why are you so insistent on doing things wrong? When you ignore the recommendations you will have worse luck with fish. Regardless of what people have been saying to you, an adult Oscar will never look good or be healthy in tanks under 100 gallons. People who say they're ok in a 55 gallon, just plain don't know about fish and have never kept Oscars until they are grown.

what are the dimensions of the tank? The oscar should have at least a 72 inch long tank.