On the marriage page right under the alphabetical buttons there is a section on Certificates.

This gives the web address of the Registrar in Douglas.
Here you can find their fees.

There are very few birth or marriage certificates for the period of interest.

As the intro page explains, the baptism is an RC one. You can see it on the film listed or from the Registrar.

If the marriage was a Dissenter marriage then a certificate will be available.

A death certificate should be available as civil registration had started by 1879.