http://www.dogshowentry.ie/ for entries and
http://www.showdogsireland.com/Shows.asp has all the uptodate show info, and posts most entry figures before the shows.
You need 4 CACIB total. In 3 different countries under 3 different judges. So 1 or 2 in Ireland plus the others will need to be in 2 other foreign countries. And there must be a minimum of 1 year and 1 day between the 1st and the 4th CACIB.
If you live in N.I. though you can get all 4 CACIB in Ireland. Or you can do what other UK residents do and once you have the 4th CACIB in Ireland transfer the dog over to someone who lives there and they apply for the Int Ch title in their name ! Yep, they really do it.