We could use “catalog” (see how the interest group for PyPI is named catalog-sig), but it sounds a bit abstract to me, and at the same time fails to convey that this module deals with finding things (in an index/catalog) and also download them (from PyPI or third-party sites).  Anyway I don’t think names can be perfect; just like distutils2.database may be ambiguous if one doesn’t know that it works with the database of installed projects, distutils2.index can be ambiguous if one doesn’t know that the repository of information (and sometimes downloads) is called an index.

+1 for distutils2.index
+0.3 for distutils2.repository (long, and mostly used with VCS these days)
±0 for distutils2.pypi