I need a different template (edit the page type) for the gallery so I can make it go full width.

The module does not actually create a .ss template file in the normal template directory. Currently the reference for the gallery include is within layout/page.ss and uses my standard page type however $Layout is within a middle column with another column to the right of it but on the gallery page I want the middle column to take up the full width of my middle column and right column.

I have attached a mockup which may explain what I want more clearly.

Just create your own GalleryPage.ss in mysite/templates/Layout. Copy the content over and change what you want. Those default templates are built to be customized, not taken at face value.

I'd also look into the ImageGallery module, which offers many more features than the standard Gallery module. http://www.silverstripe.org/all-other-modules/show/250910#post250910

I have it sorted now. I did actually create a page type (GalleryPage.ss) and thought it was not working... turned out it was just caching so it works now.