Client Options to Choose Custom Package for Work

I remember seeing either a plugin or a theme where part of the interface included the customer to choose a customized package. For example, many themes and plugins have the ability to build custom service based packages, e.g. package 1, 2, or 3. But I know there’s something out there that allows a client to choose specifics or additions to a package.

Let me know of anything that might be out there.

Thank you,