For my brooder I 'cheated' & used a herp lamp w/ a red heat bulb. I have hermit crabs & they didn't need it during the hot summer, so that worked out well.
If you wanted to cut costs you could go to the thrift store & look for a metal-encased lamp (like a brooder lamp), put in a red heat bulb (you can buy these at pet stores) & use that. Just turn it on, put a thermometer under it & see what the temp is after 5 mins. Raise or lower as needed, but not low enough that it could touch a large chick - or it might burn them!
Otherwise, I'd recommend buying a good quality brooder lamp from a livestock store & ALWAYS use red bulbs if possible. It seems to calm chicks & definitely reduces pecking.