Hi, I'm not from the Long Island area, so unfortunately, don't have firsthand information or experiences to share with you. However, I do have a resource to suggest that includes community reviews of schools (as well as test score and other demographic data): SchoolFinder. http://www.education.com/schoolfinder
From the SchoolFinder homepage, search the directory using your Long Island zip code. Then narrow your search results by selecting "private" from the school type menu (left column). You can then peruse the private schools to identify the Catholic schools. Click the school name to see its SchoolFinder page (which has the community reviews and data I mentioned).
I hope other parents in the area also chime in with their suggestions. Good luck!