I have a pair of lister clippers and i would like to know what blades i need to buy to be able to clip head/neck/chest pretty thin and blend into the rest of the body past the shoulders.  Thank you for your help.

For blending the neck and shoulders you need cover cotes and fines then learn to use them. back dragging and going against the grain or with it and pressure applied you can get the same results just depends how good you are. Get with someone who was doing it before all the specialized blades and clippers and they can help you. Or go but a set of A5 or Andis or any good set of small animal clippers and the Guards and blades for them.