CD do a Bouillon for about £6.50 per pot, but I personally buy Marigold Swiss Vegetable Bouillon (Reduced Salt). It is a sort of vegetable stock and, if you use a teaspoon in a mug of hot water, has about 16 calories per mug. This is supposed to be ok on CD. I have drunk it from week 1 when I am feeling hungry and it is very good at filling the gaps.
(You can usually find the Bouillon on the Specialist food sections in supermarkets).
I have bought the Psyllium Husks, but haven't used them yet. I will let someone else give you more "experienced" advice on these.