I've already created a database backup however don't I also need to create the XML export for all content as well if I have to rebuild my site elsewhere?
No need for that, all you need is the Database backup and your /wp-content/uploads/ directory. :)
The XML export is basically just a different format of your posts and comments database tables, it doesn't even include the uploaded media.
If you have a database backup, and your /wp-content/uploads/ directory, you have everything.
