No bells but not related.Try facebook if you are into that or have someone who can do it for you.
Telephone book is the British telephone book will shows people still living in the same areas. www.genealogy.nationalarchives.ie
Tithe records 1823-1837
Parish records for Ireland www.rootsireland.ie
and for Northern Ireland throughwww.emeraldancestors.com
both pay websites like most of Irish genealogy, but roots is a not for profit foundationwww.familysearch.org
for civil registrations for births and marriages 1864-1950's also death registrations some for persons born in the late 1700's.www.askaboutireland.ie
Griffith Valuation 1846-1862, families lived in groupings in certain areas. Look for both surnames and try to find a matching parish if they married in Ireland. Marriage in Ireland generally in the brides parish.
There are 57 Gannon's in the Mayo telephone book, 4 in the Ballina area, also 30 McGuire's with 4 in the Ballina area. Being proactive you could write to those in Ballina and see what responses you get, address is sufficient for mail delivery, no postal codes outside of Dublin.
It may take awhile to get a response so if change your email address make sure you update as rootsweb sends auto email's if someone responds.www.failteromhat.com
Directories:1824 & 1846 (I have 1870, 1881, 1894) a very comprehensive website.www.igp-web.com
+ county a good resource depending on the county
1901/1911 Census www.census.nationlarchives.ie
(families are still living in the same general areas for the past 200+ years)