NextGEN provides a platform for integrating "templates," which are alternatively gallery designs.
CAPTION TEMPLATE. Shows a caption below the thumbnail. Since the caption can affect the rendering of floated thumbnails, there is a parameter for "number of columns", to define the number columns based on your theme width. A second option is to add a ngg_gal_Columns" parameter as a custom field on the page or post. Shortcode format: [ nggallery id=X template=caption ] without space before/after brackets. This is what the caption template looks like by default before any styling...
CAROUSEL TEMPLATE. Show a main image with thumbnails below. It's a pure PHP solution which doesn't require any jQuery / JS. It requires the page to reload for each image. The parameter "images" defines the number of images that will be show as thumbnails. Shortcode format: [ nggallery id=2 template=carousel images=7 ] without space before/after brackets.