For installing User Selections of the various programs it appears we could use the mingw-get.exe XML based installer with the user selections being entered into an XML file, and then the XML file is used by the mingw-get.exe to download and execute in the correct order.
We would just have to modify the web base selections to become xml format and to save the xml file somewhere on the users machine? Then point the mingw-get program to that file somehow?
Since this is GNU software
we can use it. I have not looked into this possibility very much but I think it might work.
Here is the description from the Readme.doc
mingw-get is a tool to assist users in the management of MinGW and MSYS
installations. Configured via an online XML database, which is
managed by the project
maintainers, it offers a choice of graphical and
command line driven user interfaces facilitating selective download and
of packages provided by the project
The XML database provides maintainers with a mechanism for the
specification of inter-package dependencies; this permits configuration
of any package, such that the end user may elect to install just that
specific package, leaving mingw-get to ensure that all dependencies will
be automatically satisfied at installation