I research the Irish Family History Foundation's database. It contains 12,700,000 surviving rcds for abt 70% of Irish counties. Rcds are increasingly sparse B4 1840, rare B4 1800.
Note 1 - Without a KNOWN county, the chance of an ancestor's rcds NOT being in this database is AT LEAST 30%.
Note 2 - Only 1/2 of Co. Cork's rcds are in this database.
Note 3 - The RC church kept control over most parish rcds from Tipperary (north). These are ONLY available thru the Tipperary Family History Research center at a substantial fee (regardless of outcome).
For Joyce or Joice Wynne (+variants) B/M ???? in all Ireland, there are 0 rcds. The rcds didn't survive, haven't been digitized, or your forename and/or surname is totally incorrect. For Thomas Wilson B 1825 +/- 4 yrs in Co. Cavan or Louth, there is 1 rcd in 1824. For John Wilson B ditto, there are 0 rcds.
Google the Foundation's name to lead you to this database. Register, opt to be notified as rcds are added and browse. Pls post your search results to my genforum msg.