Frogsbit is a good start, maybe some dwarf water lettuce for thicker roots to hide in.
Something like a larger Anubias nana var. Petite, as every betta I see napping is on a leaf of that plant.
The catappa leaves also seem to make the males more excitable, and sometimes more aggressive.
blackwater works as well.
Dimming lights seems to work to calm males.
Best of luck with this project.