Ditto on polo's suggestion for wisteria...a great start up plant and grows profusely. It really sucks up the nutrients.
You can tie some anubias and java ferns to the wood. They are not nutrient suckers as the wisteria, but they grow nice and slow and are really hardy.
With that much light, you are gonna be pretty algae prone, so plants that suck up the vitamins and nutrients are a must. You may even be at the CO2 level with that light level, although with that picture, it is hard to tell what type of light it is.