Planted Tank Guru
Join Date: Jul 2010
Location: British Columbia, Canada
Proceed with your dream - it could work out very well for you.
I would urge you though, before beginning, to do a good deal of homework on discus-keeping to set you off on the right foot.
As for your questions, here's my suggestions:
1. Substrate: For the sake of being able to maintain as near ideal tank cleanliness as possible to ensure continuing discus health, suggest you consider pool filter sand.
2. You can readily grow many types of plants in PFS, using root tab ferts, such as many species of Amazon swords, Jumbo grasses, Crypts, Hygros, Rotalas, Bacopas, Lotuses, Vals & Sags, Anubias, Java Ferns, and a number of others.
As a concession to the plants, consider maintaining temp no higher than 83-84 F.
3. Assuming you go low-tech, lighting need not be more than low to medium intensity.
No particular specialty lighting - I like T5 HO.
4. Driftwood or rocks - suit yourself - but be cautious about any hardscape not having many sharp ends/edges so that the discus don't injure themselves. Leave the discus a good amount of swimming space no matter how & with what you set up.
5. Compatible tankmates are many - Several types of Tetras, e.g. Cardinals, Rummy-Noses, Bloodfins, Bleeding Hearts, Head & Tail Lights, Glo-Lights, etc.
Cories for bottom-dwelling clean-up crew; German Blue Rams; Rasboras; Hatchet Fish; BNP's - there are many other species too - just research their compatability for keeping with discus. Avoid any fish that can grow quite large and may show aggression, which can intimidate and stress discus - as well as very active, fast moving fish which tend to startle discus, or any 'nippers' - along with fish that are small enough to temp discus for lunch, e.g. immature neons.
With near adult discus in your intended set-up, you should be fine with not doing large, frequent wcs, but in order to thrive discus do nonetheless need occasional dosages of fresh, clean water, and good tank cleansing husbandry, so you'll want to build in some reasonable routine to accommodate this.
Hope this helps.
Best of luck to you !