Stay away from using domain names with doubled letters, like bb, ww, etc. This will help your website by avoiding a situation where traffic will be lost due to typos. Choose your .TOURS domain name carefully.
Build your brand with a .TOURS domain
Protecting your brand name is important, and you can do this by registering other versions of your domain name, even common typos of it. Doing this will also help drive more traffic towards your website over time.