I use extra flourescent lighting on all of my cages. I have had no adverse reactions. I have gotten my hibiscus to produce buds under these lights pretty consistently but only on the upper quarter of the plants. I have switched brands around a bit the latest is the cheapest. Guess will see how that works out in a couple more months if the plants are still holding thick like they have been.
I have been using lights in the 6500-6700K range. K stands for Kelvin. Kelvin is a measure of heat. The heat rating is directly tied to the type of light that these bulbs will produce. Say one in the 2800-3500K will be more blue to purple. One in the 5500-6500K will be more on the yellow to red side. If you where just going to add one I would go with one with a higher Kelvin rating. Plants find this more useful. This is also true with most incandescent bulbs. They generally produce light in these areas. They are not near as effective but they are way cheaper over the long haul. These flourescent bulbs will have to be replaced every 6-12 months just like your UVb ones.
I would probably steer clear of these types of bulbs rated at 10,000K. These are designed for reef aquariums. They do produce quite a bit of UVb to my understanding and am unsure as to what might happen.
Alot of these bulbs produce UVb. They do not show the ratings that low because as Brad said plants do not really need it. If to much UVb is present it can cause problems with plants but not the other way around.