There are two problems with Toolkit that I see. First is that it uses a source filter to do its work, and that is almost guaranteed to become a problem eventually. Second is that it is meant to load one set of modules that are defined per-machine.
I think ToolSet is generally a better choice. In addition to not using source filters, it is meant to build your own modules for including groups of prerequisites. Being based on modules like this instead of a single per-machine list makes it redistributable as well.