Reptiglo if you're talking about CFL bulbs. Reptisuns have been associated with manufacturing problems that cause eye problems in the past. They claim to have fixed it but there are still some old faulty bulbs floating around. If you're talking about linear bulbs it makes no difference.
5.0 is usually preferred because the number correlates to the concentration of UVB in the bulb. 2.0 is for dense forest ground dwelling animals that don't get much sun. 5.0 is for mid forest level animals that get some sun regularly but not constantly (like chameleons). 10.0 is for desert animals that always see sunlight (like bearded dragons).
I use Reptisun 5.0
I've never had any issues related to the lighting, my chams seem happy and healthy.
Just be sure to remember to change the bulbs, over time they will lose their ability to put out the proper spectrum and they'll cease to be effective before they will actually burn out (it'll look like it's working fine, but it won't be).
I change mine every 8 - 10 months.
Do you really have that much luck and they last 8-10 months? I am new with my panther, but have been keeping Beardies and various snakes and geckos for over 20 years. I have never gone over 6 months with a bulb. Even at 6 months I have had bulbs tested and over half of them have lost more than 40% of their effectiveness.
I would love it if they produced one that would last a year I would not have to spend so much money every 6 months (14 new bulbs + 1 now)
I can get 8 - 10 months because I use them sparingly during the early summer and early fall when the weather is nice enough in Oklahoma to utilize some natural sunlight... If you subtract off the equivalent of the 2 months or so I use mostly natural light, then you'd be right back at 6 months... I probably should have clarified that in my first comment
I had all my Chams on reptisun 5.0 except one that one was on a reptiglo 5.0. The only chameleon that I have had any health problems was the one on the reptiglo. It was a female veiled that developed eye problems and died a few days later. Not sure if it was the light but that bulb was the only difference between her cage and my 7 other chams and every other one is doing great.