I am looking for a junior book(s) that I read between 2001-2004, I do not know when they were released. They were about a brother and sister in a futuristic world where your clothing indicated your status or what class you belonged to. Their father worked in genetics and I can't remember exactly how it goes but I think they end up being cloned or specially designed. They are given a genetically enhanced dog as a guardian. Other things I remember are virtual reality competitions/classes, homes with artificial intelligence and segregated rings of society. I would really love to revisit these books if anyone can help me.