Some Catholic Church records for Westmeath are now available online at:
http://westmeath.brsgenealogy.comI found my grandmother's baptismal certificate and her parents' marriage certificate there.
The system is shall we say odd, with respect to payments. Index searches are free, but generally do not provide enough information to determine whether a record is one you want to see. Viewing a record costs 5 Euros regardless of whether it is or is not one you were looking for. No flat-fee or subscription service is available.
For my grandmother I already knew her birth date, so I could be assured it was her baptismal record. For her parents' marriage record I could search for them individually to ensure there was one record for two people with those names married in the same parish at the same date. But in general the price is too high, for me, to allow me to use the database well.
The staff at Dun na Si Heritage Centre was helpful but the IFHF staff was not.