Alternate package repository

I added a static application to create a personal package index, similar to PyPI but containing customized packages (eg, a tarball of PIL with tweaked Library pointers). Now I want that when I run pip install something, the lookup to retrieve the package is done against my personal package index first and then, only if no package has been found there, on PyPI (like an override).

I tried this and it worked (PIL 1.1.7 locally, PIL 1.1.7 on PyPI):

1

pip install --find-links http://packages.myusername.webfactional.com PIL

but reading the docs about alternate package repositories I'm not sure this command does what I want:

Like --extra-index-url, --find-links is additive by default, it does not replace or supersede the index. All package sources are checked, and the latest qualifying version for every requested package is used. If you want only your --find-links URL used as package source, you need to pair it with --no-index.

Does pip install Package 1.1, if it finds Package 1.0 on the local index and Package 1.1 on PyPI? In this case, how to force pip to install the package found on the local index? I can't use --no-index to exclude the default index because it is meant to be used as the fallback package repository.