I honestly don't think they need that much light. I grow my highland nepenthes under two light fixtures, one a 20w T5, the other a 20w T12. The T5 is 18" over the small ones or 6" over the tops of the big ones, and the T12 is 3" from some and 12" from others, depending on location. They grow like weeds and are doing super well. I would go with whatever is cheaper (unless there's not much of a difference, then go with higher wattage) as long as you make sure they are getting the correct spectrum they need. My T5 and T12 are aquarium lights and look pretty blue, so they may not even be in the correct spectrum for plants, but they still work. JME.