One problem with low light is that the plants that do really well, growing at a decent rate, in low light, are almost certain to be noxious weeds. An example is Hygrophila polysperma, which is so bad a weed that you aren't supposed to transfer it to anyone else. But, it grows very well, and looks good, in a tank with a PAR of 20 or even lower, especially if you also use some CO2. I have it in my low light tank, and have to prune heavily weekly.
Another good one for me is Nymphea zenkeri, red lotus. I have been cutting off the big leaves reaching near the water surface, almost every week. And, it looks good against the bright green H. polysperma.