You will want to look at low light plants, and here is a wonderful guide with photos:
http://www.plantgeek.net/plantguide_...=1&filter_by=2
Plant geek is wonderful for plant information :-) You could try some of the medium low light plants but low light ones are going to be your best bet. In addition, until your tank is really grown out with plants your fish will likely provide enough CO2 for them.
http://www.plantgeek.net/plantguide_...=1&filter_by=3
I am also trying a 29 gallon planted, and had about 18 watts with a lot of natural sunlight as well and only the low light plants grew at all. I just upgraded to a 2x65 watt 10,000k compact flourescent fixture I got on ebay in hopes that my red plants will actually turn red by having enough light.
Here it is so far:
http://www.fishlore.com/fish-picture...ge-265-16.html
I am hoping that is a good "before" photo and that I will have some nice growth in the next few months!
--R