We use horse bedding pellets. There is still dander but that cuts it way down, plus, less maintenance as the pellets are good in there for about a month. Coccidiosis can't grow as they dry out the poop.
We use 150 watt in a UL approved holder. For that small of a brooder it may be okay size-wise if you put it in one corner, and the food/water in the other.
We have an Inkbird thermostat too which helps regulate.