Two sets of double bottom-heat boxes. The lower one with one regular light bulb socket in each is the first one I built. After experimenting with different wattage's I found that a 7.5 watt regular light bulb (which is more expensive than brighter bulbs) was sufficient most of the time. I monitor temperatures at all times!!!
Eventually, I got the idea of using faded-out outside Christmas lights (that had 7.5 watt bulbs) of which I had lots - obviously much cheaper!! As you see in the upper box, I started with three lights. Three lights were too high for starting cuttings, but were OK after the cuttings had rooted and were transplanted. I now have a set up for 4 dish-pans side by side, 4 boxes in one with only 2 Christmas lights each - this just fits under a 4 foot double fluorescent light fixture.