Unlimited journeys with London tube saving money?

Hi, I will be soon in London for a week and I have two questions: 1) I need a type of ticket that allows me to do unlimited journeys everyday with tube inside of London without paying £4.50 again and again. What kind of solution can you suggest me? 2) If it is also possible to do unlimited tube+unlimited train+unlimited bus all of them inside of London. What would be the saving of money? Thanks in advance for your help and explanations.