Getting enough light on a planted tank to get the plants growing well is very easy to do with the many lights that are available now. That wasn't true 20 years ago. So, why not just get a single light that provides enough light for the plants, but not so much that it is a major challenge to avoid algae problems, and use it both for growing plants and for viewing? Then, rather than playing with lights, spend your efforts getting a good CO2 supply to the plants. That will do far more for the plants than anything you can do with the lights.