This link will help you *try* to determine the sex:
http://www.beardeddragon.org/articles/sexing/
Note: You said earlier you were interested in breeding them? If you got them from the same place they are likely siblings and should NEVER be bred.
About temps: What are you using to measure the temps, I hope it isn't a stick-on "reptile thermometer" strip those aren't accurate at all. Use a digital thermometer with a probe on the hot spot (go to wallmart's garden section to find one). The hot spot should get between 95*-105* F.
About light: Get a UVB flourescent light. A good one is Reptisun 5.0 or Reptisun 10.0 by ZooMed, these provide D3 which is essential to a growing BD. These lights are NOT the same as the heat lamp, you can use a regular household bulb for heat (what you pay for at the petstore is a normal bulb with a lizard on the package). While a Reptisun bulb may seem expensive, keep in mind that it is the very best UVA/UVB flourescent on the market. Also, you should put your lights on an inexpensive timer (the kind you could find at wallmart for ten bucks) this saves you the trouble of switching the lights on and off, and creates a more stable routine, with less stress, for the BDs.
-Drew