I use 6% and 12% bulbs, but I also know the difference in when and how to use them.
I'd recommend you chat with Todd over at lightyourreptiles.com. The guy is phenomenal with his knowledge of light systems and how they interact with habitats. He's a sponsor on the site too. For a such a tall cage you might go with a combo of a 6% light and one of his jungle spot lamps to reach the bottom. I'd cut the top off that cage so I could put a screen top on it and the light fixtures upon it.