Hi,Single or double entry visa

I am visiting Beijing for 4 days and then traveling on to Australia for 2 months. On my return to Ireland from Australia (with Qantas), we arrive in Beijing airport at 22:00 on November 25th and depart (with Qatar airways) at 01:30 on November 26th. I wish to arrange any entry permit requirements in advance of my trip, to avoid any delays or complications at Beijing airport. I understand I can do this via the Chinese embassy in Ireland. Can you please confirm that this is so and advise whether I will need a single or double entry visa. Many thanks.
Eddie Brennan