Because I'm cheap, and didn't want to run a 250watt heat lamp during our 'peak hours' from our electric company, this year I decided to try a heat plate. Again, because I'm cheap, I didn't go with one of the big-name, $100 jobs. I decide to try out one at my local Tractor Supply.
https://www.tractorsupply.com/tsc/product/producers-pride-brooder-and-coop-heater?cm_vc=-10005
I really like the way it has worked out thus far. Our chicks are 2wks old, and have been perfectly content with this plate. The 8 of them easily fit underneath it, and with it set up lower in the back/higher in the front, they can easily adjust to whether they need/want more or less warmth. Also, it's nice that they have dark for the nighttime.