Hi,
Have you tried the Gallery block? You can turn off the thumbnails: https://support.squarespace.com/hc/en-us/articles/205813728-Using-the-Slideshow-Gallery-Block
You can add a search bar with the Search Block and add it when you're in Style Mode, no code required:http://help.squarespace.com/guides/using-the-search-block#toc-add-the-search-block