If you really are concerned about the future, your best investments would be in a good scale and a magnetic stirer. Couple these with the Darkroom Cookbook and the Film Developing Cookbook and you'll never have to rely on Kodak, Ilford, Agfa, etc. Stocking up on premixed chemicals is not a wise plan IMHO; even some raw chemicals don't have a long shelf life. Good sources for raw chemicals are Artcraft, Bostick & Sullivan and Photographer's Formulary. unblinkingeye.com is one online source for numerous formulae.