All of these registers are freely available to the public but this is strictly a do-it-yourself option. There is no research service at the Library. You have to visit in person, or hire a genealogist to do the research for you.
Most of the original registers are in local custody and are unlikely to be made available for public browsing. If you have precise dates for your ancestors's birth/baptism or marriage, you could contact the local priest and offer a donation in return for a 'look-up'. In my own Irish genealogy research, results from this approach have been mixed.