Although people use plastic totes all the time, they do tend to verrheat the chicks, and they have limited ventilation, plus minimal space. At 4 weeks they should have at least 2 sq ft each, plus more space for feeder and water. Cardboard boxes make great brooders; they breathe, they are expandable with some duct tape and another box, and they don't require cleaning when you're through with them.
I agree about temp; you won't really know til you get them in there and see how warm it is with the air flow for your setup, your indoor temp, etc. A 250W bulb is almost always too hot indoors; I'[d suggest having a variety of incandescent bulbs. By 4 weeks if will indoors you probabl won't need any.
You could also brood right in your coop, if it's ready and you can safely rig a heat lamp. Or your garage or whatever, just depending what you have there. Check this outL
https://www.backyardchickens.com/t/735392/redneck-fungshui-brooding-17-degree-temperatures