As to the UVB lights, I would go with the 10.0 over the 5.0 if buying tube type UVB lights.
You can also order mercury vapor UVB lights on the internet which would be superior to the fluorescent tube type. Tube type UVB lights have to be REALLY close (like 6-8 inches) to the iguana to properly benefit the animal.
What country are you in? Does your iguana get to be outside in the natural sunlight much?
How is your iguana's diet? Are you able to get recommended greens etc where you live? If you ig has a proper diet, the supplements shouldn't be necessary, but hopefully others that do use them will chime in on the best products.