Need Help with setting up new tank

This will be my first Discus tank. I was thinking about a 150 gallon or bigger with 6 Discus, 10 Neon Tetras, 5 Rummynose Tetras, 5-10 Harlequin Rasboras, 2-3 Albino Bristlenose Plecos, some Gold Dojo Loaches or Black Kuhli Loaches, maybe some Cory Cats or Bumblebee Catfish and my GF & Kids really want a betta but I don't know if it would work in the tank. It is going to have rocks (Granite, Texas Holey & some flat rocks), driftwood (Mopani), and will be planted with Java Fern and probably Dwarf Hairgrass. Please tell me what you guys think and any advice would be greatly appreciated.