I wouldn't use those red heat lamps because they concentrate the heat into a small area that could cause scorching or overheating that one area.
My hot box has 4 ceramic light sockets. I started out with 4, 200w incandescent bulbs but reduced it to 4, 100w bulbs. I also have a thermostat that shuts it off at 168deg. For lower temps for drying wood I will unscrew a bulb or two to regulate the heat.