The ceramic coil really works well. As long as they are in a place that has sunlight in the daytime. If not, you will need a light source during the day.  The red heat lamps work at night, but they do soak up the meter reader. If i could find a 100 watt red (not colored) heat lamp,  I would change out all my 250 lamps.  I use the coils when the chicks are in the house. Then when they go to the nursery (outside port. building), they get the white lights. 
I have a quartz heater in the building and the temp. stay at about 60 degrees give or take 10 degrees. If you look at the table for a 5 week old chick you get.... 95,90,85,80, 75 for 5 weeks and the next week it is 70 degrees. So really 60 under a heat lamp is pretty good. I leave the lamps on for two weeks and then they are turned off. The quartz heater is always on and the port. building has a window. At 7-8 weeks a good temp is 60 degrees and the guineas are usually finding their voices by then. I can identify who the females are too. The chickens are fully feathered by then. I wait until the chickens get to about 3-4 pounds (standards) and then they go to the main barn.