Yeah: has no chance. First off, your wanting a 30 inch fish, a 18 inch fish, and other large fish with fish less than 2 inches. Those would be gone right away. Now, you could Mabye (and keep in mind I know near nothing bout large tanks or fish)
So Mabye a Oscar, a school of clown loaches and a School of large barbs(rosy barbs get 6 in. And is a good option. See what others think, but your kinda throwing fish out they that aren't near compatible