Hornwart, Moneywart, Dwarfhair grass(Wont spread much but should still do fine) some bamboo, duckweed... From this group only hornwort floating and bamboo which can only have it's lower third part in the water is suitable. Duckweed is messy so steer clear.
You have very low light and the most tolerant of low light plants are Crypts which are planted in the substrate, then Anubia, Java Ferns, and Bolbitus which are attached to rocks or driftwood. If you use any Crypts which would look very nice if you used Crypt Wendtii Red or Bronze will need to have root tabs inserted under them as they are heavy root feeders. If you would use hornwort to float be aware they can be messy plants and shed those fine leaves all over your tank. That is a plant I avoid using even in my ponds and never in my tanks.
