I agree you will need someone with family information. However, if there are records prior to 1899 they will be with rootsireland and you have tried there. You are unlikely to get responses from clergy as that is why they donated records to the Foundation as they don't have the time to answer the hundreds of requests they get. People who have even visited the churches have found in most cases clergy not too willing to help out.
Were the family RC or perhaps Church of Ireland as most people of means were Protestant?
Also RC and other religions if there was no local chapel for them would be baptised in the Established Church which was Protestant. The majority of the population were RC but few churches and it was not considered the Established Church. Same thinking regarding it being illegal to educate catholic children. Protestants were the dominant minority.
There is a Representative Library for the Church of Ireland in Dublin. They have the majority of the parish registers that survived to 1900. You must visit in person and do research yourself or someone you hire to do it. I was in contact with them yesterday and they gave me the name of a genealogy research firm. www.apgi.ie