Unfortunately those packages are not targeting Database First scenarios. For such scenarios you need the full-blown Visual Studio integration, which is currently not available as a Nuget package. However, this idea is already on our list and you can see such packages in the Nuget repository in the long run.
OpenAccess ORM Q2 2013 brings you a more powerful code generation and a unique Bulk Operations support with LINQ syntax. Check out the list of new functionality and improvements shipped with this release.