I am currently researching the Magherafelt Church of Ireland records and have found a number of Peacock's listed. Let me know if you are interested.
Also, because you have roots in that area of Ireland, you are eligible to join a free "Rootsweb" genealogical discussion group called Ballymaguigan Roots. It consists of others who trace their ancestry to that part of Ireland and we exchange information that helps everyone's research.
Let me know.