I love PetSilk products. I order them online and they are very reasonable. What I use is a 12 oz bottle that can be diluted 16 to 1. So it lasts a very long time. I also like the Silk Serum they offer. My three have the most soft and shiney coats. At this point I can't see ever changing.
http://mjm-petsilk.com/catalog.htm