For a low light planted tank application, i think the Ecoxotic fixtures might be overkill. Without the addition of co2 and faster growing plants, you'll end up with a lot of algae. The Ecoxotic might work if it's suspended real high. Measure the distance from light source to substrate to get the PAR value between 10 to 30 for a low light / low tech setup.
LED Lighting Compendium
as your guide to get the right estimated PAR.
For a low light tank, the Finnex Fugeray would probably suffice and not cost much.