Question: If I wish to Nianfo (practise mindfulness recitation of Buddha’s name), will any Buddha’s name or mantra do?
Answer: If your objective is clear, to reach Amituofo’s (Amitabha Buddha) Pure Land, and since support-chanting is usually using Amituofo’s name, it is best to stick to his name. Amituofo’s name also encompasses ALL Buddhas, Bodhisattvas and mantras, as can be seen at https://purelanders.com/2017/03/29/should-i-chant-many-mantras
Although any of the above can lead to Amituofo’s Pure Land if powered by the same Three Provisions: https://purelanders.com/2015/12/30/%e5%be%80%e7%94%9f%e5%87%80%e5%9c%9f%e4%b8%89%e8%b5%84%e7%b2%ae-the-three-provisions-for-rebirth-in-pure-land, it is still the easiest to be directly mindful of Amituofo’s name, which is very short, easily allowing us to connect to him. Thus, unless there are good reasons not to use Amituofo’s name directly, it is best to stick to it. You can use this track as a guide: purelanders.com/mp3