If you get adult hens, they won't be used to you and you won't know their personalities as well as you would if you started with chicks. Chicks are just so cute, I don't see how anyone could resist. But they do need extra care and take up more time then pullets or adult hens. You mentioned you are going to start with some hens, which is great but if you also want chicks, DO NOT PUT THEM IN WITH THE ADULT HENS. They are not like dogs, the adult hens won't help the babies, in fact they might pick on them. If you want to introduce new chicks to the hens, do it when they are older and can defend themselves. Best of luck.