They need at least 1 foot per chick at minimum. I have a 110 gallon watering tub that I use. I am able to clean really well between raisings.
The dog kennel will work as long as it is a hard shell one with a small holed grate in front. Your chicks are going to fit in the palm of your hand when they get there, so make sure you cannot put a gum ball between the grates or the chicks will get out. The buggers are fast too if they escape, and everything wants to eat them!
Do not keep them in the dog kelnnel long because they are going to double in size each week so it is going to be hard for them to have space in a very short time!
Hope I helped a bit!
Welcome! I would start with the box, and plan to enlarge the space from there. If these are standard sized birds, they get big FAST and will need more space soon. I use an oblong stock water tank, sized for 100gallons, with a hardware cloth top, and the heat source at one end so there's a temperature gradient. Mary