First off welcome and enjoy the ride !
You have now idea what your getting into. Lol. Discushysteria!!
I would suggest you do a lot of homework. Your lucky to start here and lay out a plan first. Read read read. Read the stickies. Watch ALS talk and read some more.
A few points. Get rid of the gravel. If this is your first go round bare is best or some light sand. Paint the bottom sides and back of the tank first.
86 is way to high no need. 82-84 is fine.
What type of decor ? If it's rough or pointy toss it. Some nice driftwood is great for discus
Heck of a mixof fish. Some ive kept some others not so much. Just make sure they re peaceful and not fierce eaters. You my not think they are "aggressive fish" but if they are fast to food and too active your discus can spook.