UVB Lighting

So my biggest fluorescent went out and Ide like to replace it with a uvb light after learning about its effect with marijuana growth. Im curious what to look for when buying a uvb bulb. I did a quick search and found a bulb that will fit a regular A socket. Let me know if I am on the right track or there is something better.

light: http://www.amazon.com/Zoo-Med-ReptiSun®-Compact-Fluorescent/dp/B00061V53Y

Just making sure you mean as a supplement not as your only lightsource right?
From what I have read about UVB if you don't have a certain amount, it really doesn't do anything.

it will be going along with my usual setup of 8 42w cfls.
I used a 85w in the middle but it went bad, looking to replace that.
What would be a good amount?

Once again let me stress, my only information is read, but what I have read says basically you need a handful of the bulbs to produce any real difference. A single bulb, or even two bulbs isn't going to do much if anything.

Very well then, I will just replace my 85w then.