Newbie Tortoise Question: Lighting

[Linds]

Now from all I have researched these guys need UVB. Well, the lighting and stuff I picked up yesterday was a clamp lamp with a blue UVA bulb. I didn't read the bulb carefully, I just saw that it said UVA and UVB, now had I read closer it would have read "contains UVA and can be combined with reptisun 5.0 for UVB...." Now I have seen these guys housed with just those blue bulbs before, and have been told that it would prolly be ok, but I am not well versed on lighting since most of my kids are nocturnal, figure I had better check. I don't want to have improper lighting, but don't want to spend $100 if I don't need to either.

Another question...... is there a reason they don't make UVB bulbs (the kind that screw in to the lamps)?