On OS X, you need to build Mapnik from source to get it to work with a virtualenv + homebrew python. Steps:

1. Install Mapnik Dependencies without virtualenv activated (which will ensure boost-python bindings will be linked correctly to homebrew python)

2. configure, make, and sudo make install Mapnik with virtualenv activated.

The configs that TileStache needs are in the tilestache directory. After pip install-ing TileStache, these scripts should be in the bin directory of your virtualenv so you should be able to run them like so with your virtualenv activated:

$ tilestache-server.py -c tilestache/tilestache.cfg

Or with gunicorn:

gunicorn -w 3 -b 127.0.0.1:8080 "TileStache:WSGITileServer('tilestache/tilestache.cfg')"