I want to put in a small light to help the plants (even though they're good for low light). Any suggestions?

I've read some stuff about UVB lights and how that might help. I'm pretty sure cresties don't need a full spectrum light, but would that be benifical during the daytime?

Also, how high of a wattage should I aim for? The house will not go below 65 at night (acutally I think I set it to be 68 since I got herps), and it doesn't go above 80 in here.

The book I've got says no more than 40 to 60 watts, but I'm thinking that might be too high. There are a bunch of 25 watt lights, but I'm a bit confused on which one I should get. Some of them say that they are day lights, but there's no info on the box.