The phrase "Γι αυτούς που αγαπώ, θα θυσιάσω" is not equal to the others and it's not completely grammatically correct.
θα θυσιάσω comes from the verb θυσιάζω ( = I sacrifice somebody or something). This verb is transitive, it needs an object. In other words you need to say whom you sacrifice. It would be grammatically correct if the sentence was: "Γι'αυτούς που αγαπώ θα θυσιάσω τον εαυτό μου." = " For those I love I will sacrifice myself".