Theme for building up custom travel packages

Hi everyone,
I am struggling to find the theme I need, in order to work on a project of custom travel packages.
The idea is to have a website where the user can create and customize his / her own package, by adding up single activities, rather than finding a pre-organized package.
I already know there are excellent themes in ThemeForest, for tour operators and travel agencies.
However, I can’t see in them the functionality of adding up single activities and making them become a full package.
I would appreciate if anyone could recommend a theme that is capable of doing this.
Thank you