Seeking Sextons Hayes or Clooney O'Rourke from Cork

I am trying to locate where in Ireland my Paternal Great Grand parents came from in Ireland. My cousin thinks he remembers relatives saying they were from County Cork.

Here's what I know  My Paternal great grandfather John Sexton  was born somewhere in Ireland around 1856 to James Sexton and Mary Griffin .I have no other infomation about James ands Mary.  J

John Sexton married Mary Ann Hayes who was born in New York state around 1851 to Michael Hayes and Honora Harkins both of whom were born in Ireland. Michael and Honora were married on October 26, 1844 in Cork. My notes say they were married in Cork, Cork, Ireland. So I'm hoping this will help me find their parishs.

On my father's mother's side is Michael Clooney born in Ireland around 1850 to Michael Clooney and Ellen (last name unknown)  and Mary C O'Rourke born in Ireland around 1849 to John O'rourke and Mary (again last name unknown)  

Michael Clooney became a citizen of the US july 12 1875 in the City of New York. He and Mary O'Rourke (in some places she is called Mary C O'rourke) were married on Feb 21, 1871 in Manhattan, NY. Michael may have immigrated in 1867.

I know these are all very common names but I'm hoping it may ring a bell with someone.  All four lived in Hoboken, NJ at some point in their lives.

If there is any other info that might help, please contact me and I will see if I have it I know most of the names of the children and grand children born in the US.

Through DNA I have found very distant relatives in Clare can find no common ancestors there or any match to these folks.  Many thanks for any assistance you can give.  My goal is to locate all my Irish forebears and then plan a trip to visit their parishs.

Kathleen Sexton Hall