We went a little over-the-top with two cats who like imagining they're tigers. We used a big ol' plastic tub with a hardware cloth top inside our friend's great dane's dog crate for 4 chicks. You would definitely need to add hardware cloth or something around the outside of the crate if that was your primary brooder, as the chicks were able to squeeze through it until they were about three weeks old-and ours weren't bantams! You'd probably want a 36-42" crate or so. That way they have space to move around as they grow. I'm assuming that by heat pad you mean plate? If so, I'd highly recommend it. It would be ideal to keep them in an unused bedroom or large closet, but I'd definitely understand if that wasn't an option. As long as your basement isn't freezing cold, the chicks would be fine down there with a heat source I think. I can't remember what age I moved them to the coop unfortunately- however, I believe it was between 5 and 6 weeks. As long as you put them out once they have most of their feathering, they won't need a heat pad as they can keep each other warm. I believe cochins are a pretty friendly breed, as are orps and golden comets/golden buffs. Good luck!