You can get anubias, java fern and moss to be attached on wood. They are very hardy and do well in low tech tanks. Corys love the shade of driftwood branches and caves and if setup high enough, you'll see the corys more in the upper levels of the tank sniffing around the anubias and even laying on the leaves.
Amazon sword would do well in a low tech tank if you give them some root tabs as they are heavy root feeders. The corys in one of my tanks love gathering at the base of a big amazon sword. Most cryptocoryne species adapt in a low tech and would also like some root tabs and take similar shape to amazon swords.
Floating plants are also a very good option as they use CO2 from air and are very good nitrate and other nutritient sponges. They'd protect the tank from direct light too which again the corys would like.
Corys are great fish, my favourite by far. Good luck with yours.
