Matt,
For the most part, the type of lighting needed to make bromiliads color up and produce new pups and blooms will have to be provided by power compacts or multiple higher output T-8 or T-5 flourescents. In a small enclosure this will put out way to much heat and light for brevs or phants.
Not to mention the smelly, bacteria ridden mess that I guarantee will occur when crickets drown and rot in the waterfilled axils of the bromiliad.
The plant itself will probably rot from being planted directly in th moist substrate. They naturally grew higher up in trees where the get lots of sun and the base of the plant and root system stay relatively dry while still being able to collect water. They can be used in vivariums, but have to be placed stratigically.
I am glad you have choosen the wellfare of the animals over your own preferences by upgrading to a 20-30 gallon enclosure.
Stick with the ficus, ferns, and viners. These are the best type of plants to use with these guys in my opinion.
One Zoo Med 2.0 bulb will be sufficient to grow these types of plants as well as providing beneficial UV spectrums to your geckos without over doing it....as our research in this area is somewhat limited at this point in time.
Hope this has helped. ;-)