Unfortunately, because you are located in the UK (I'm assuming from your location, correct me if I'm wrong), the products that are available to you may be different from what we have here in the US. (Though who knows? Maybe they have them there, too.)
If you are just getting started showing your dog, don't worry too much about the products that you use... there is so much for you to observe, learn, and pay attention to, and as Chris's friend suggests, there really is no "magic" product that will make your dog look amazing.
Your best bet is to ask your dog's breeder, other people who show Shelties, and other people who show similar breeds (like Collies). They will be able to help you with products that are available locally, and will be able to help you technique as well as product.