Implement a similar mechanism with el-get as for elpa.

That is storing the package list into a file, tracked by git then.
Remove most of color-theme, and packages coming from github or other unreliable sources. And re-install hl-sexp.
Implement for 'el-get the same upgrade triggering mechanism as for the 'package repository.
Implement an advice around 'el-get-package-menu-exexute in order to automatically update the package list file