How can I bundle different installers from third party vendors to ease end-user installation process
pkgbuild and productbuild
Apple provide two command line tools for creating installer packages on macOS:

pkgbuild
productbuild

These tools handle authorization. Options are handled by the distribution file passed to productbuild.
autopkg 
autopkg is an open source tool popular with Mac administrators:

AutoPkg is a system for automatically preparing software for distribution to managed clients. Recipes allow you to specify a series of simple actions which combined together can perform complex tasks, similar to Automator workflows or Unix pipes.