I think a package installer should be more generic:
1) Define a package installer format.
2) Create a universal package installer function and repository that is able to execute and installe the packages in the format defined in 1) into the websites.
A remoting function is only a wy to insert data into the mysql database on the master server, it can not execute any code to install software on the slave that runs the webserver. A package installer would have to be implemented as server side module plus a corresponding database table and some inteface forms to select the software that shall be installed in the website module.