You haven’t said what denomination these families were. If they were Church of Ireland then the following records exist for Seagoe parish:
Baptisms, 1672-1731, 1735-1821 and 1829-76;
marriages, 1672-1731, 1735-1821 and 1826-45;
burials, 1672-1731, 1735-1821 and 1829-81;
Analysis of register of baptisms, marriages and burials, 1672-1904.
Index to baptisms, marriages and burials, 1672-1919.
There’s copies of the above records in PRONI (the public record office) in Belfast. No other denomination has any Seagoe records for the 1700s.
If any of the families were farmers then they should be listed in the tithe applotment records in 1834. Here’s the tithes for Seagoe: