I am using a 100 watt bulb with a little reflector cone thing in my brooder (I only have 4, so it isn't a huge space I am having to heat). Since the brooder is inside they have been quite happy and comfortable. I even had to move the light up the first day because they were too warm.
Also, because I couldn't find a red bulb (which is supposed to help reduce pecking and helps them sleep better), I just bought some red tissue paper for $1 and put that on top of my brooder, right below the light. It gives the same effect in the brooder as a red light would. So far it is working great.
I think you could definitely get away with using a regular light bulb as long as you are keeper the brooder inside and as long as it is not a huge space you are trying to heat.