I got my gentle leader directly from Petsmart. I only searched online to give you a better idea as to what it looks like. I didn't even read the site! But, all I have is the leader. It's up to you if you want to get the other stuff they offer. Just read up on it and make sure the things you do buy will benefit you and your dog. As for having the harness, too, I wouldn't think that would be necessary. I have Finn's collar on him all the time, because of his tags. I leave the leader hooked to his leash, and, when it's time to walk, I just slip it on and that's it. Before I had the gentle leader, I had his collar for his tags and his harness. Originally, I kept his harness on all the time because he was being potty trained and was going potty every ten minutes. So, it was a matter of saving time by leaving the harness on all the time. Anyway, I would replace the harness with the leader, if that's what you want, but, I wouldn't do both. Maybe a collar, too, just for his tags. Good luck!