You can look at the library index - which includes the parish records - at the LDS site on www.familysearch.org. Click on the Library tab and go to the Family History Library Catalog. The Place name search will tell you if there are parish records in their catalogue - which there should be for the Island. You can search at your leasure and get all the details, film numbers etc. and you are then in a position to order the film when you visit the Family History Centre.
Mind you, the detail that was recorded in the records was very much up to the Incumbent - some recorded more than others!
Roger