Ancestry doesn't have many Irish records in its database which is why you weren't able to find much there. LDS site (
www.familysearch.org) have a bit more in the way of Irish records but not really anything as recent as you are now looking for (for example, many, not all, Irish births 1864-c1882).
LDS Pilot site has recently added index to Irish civil registrations (birth, marriages, deaths) and for Northern Ireland the index goes up to 1921.
http://pilot.familysearch.org/recordsearch/start.html#p=collectionDetails;t=searchable;c=14083471901 census is available from several sources (not online yet- it will be added to National Archives website after they get 1911 for all Ireland done) such as PRONI, some Northern Ireland libraries like Ballymena, and LDS libraries. You can order 1901 census from your local LDS library for a small fee if they don't have it in stock but as it's not indexed you have to know which film to order.
Details of living people, or recently deceased people, shouldn't be posted here. If you want to send me a PM I'll try to answer any questions you might have that can't be put on this thread.