GFI outlet in bathroom

I have a powder room with a heatlamp in the cieling, an incandescent light over the sink and no electrical outlet. The two lights are controlled by a two switch box. I bought a combo unit; a switch to control the light combined with a GFI outlet (the switch does not control the outlet). My question: can I replace the heatlamp bulb with a regular light bulb and wire both the former heatlamp circuit and the incandescent light over the sink to the single switch? Or do I need to forget about the heatlamp circuit altogether and just wire the incandescent over the sink to the switch? I'd like to be able to use both lights (and we don't need the heatlamp). If I can't use the heatlamp circuit the only alternative I can think of would be replace the incandescent over the sink (which has only one bulb) with a larger fixture with more bulbs. Opinions please?

 

Before you can install the combo unit you will need to determine if all the necessary wires are in the switch box. You may only have a switch loop.

If all the necessary wires are there the combo unit as you described it should replace one of the switches with a small wiring change.

You may have more than one circuit in the switch box. You will need to describe the quantitiy and colors of the wires attached to the switches and any other wires in the switch box.