Ill warn you that upgrading the bulb wont really help that much, it will help but wont change what types of plants you can keep. Id tell you this, Get plants that are the size you want already that require low light, Dont get anubius its a black hair algae magnet. The reason I tell you to get large plants is because your light wont allow them to grow much but will only support their life possibly most likely even java fern will just turn brown and slowly die. dose some excel it will help alot and use root tabs because the plants in that low of light will benefit most from root tabs RIGHT next to the base of each plant because with that low of lighting they wont grow very long roots. If I was you I would pick up a t5ho from fish need it. the 2 bulb 24inch fixture is only 73$ with shipping, you will be able to grow many more plants and they will actually fill out. If you have any questions let me know Ill be glad to help you with FW planted its my specialty
T5-HO Light
If you havent bought the tank yet just get the 29 gallon w/o hood and get the t5ho fixture, if you want a planted tank you will be MUCH happier with a light beings thats 75% of a planted tank without Co2 and the other 25% is doseing the right stuff.
Check out my tank if you need some ideas in my sig, Its a post of my whole build with somewhat up to date pictures Im letting my tank fill back in before it always looks a bit scraggaly after a trim and replant haha