How to use full width pages AND pages with sidebars

Hi, On my website-under-construction I'd like to use both full width pages as pages with one sidebar. I found a lot of lay-out options, but I wasn't able to figure out how to get this working, because the templates in the page overview (quick editing) don't support this. I was searching for the combination 'lay-out-options' and 'overwrite that by choosing another template for a particular page'. But I couldn't find that. Can I get this working? Or do I need a programmer to add a full width template and set the rest to 'right sidebar'? I'm looking forward to you answer. This site is still under construction, but if needed I'd love to send you the login details in a private message. Thanks in advance!