Satchless_heroku_skeleton is a project mainly written in Python, it's free.
Basic structure for a django app using satchless on Heroku + S3
At this present satchless is part of the repo and kinda sucks...
Still to figure out why -e git+git://.....#egg=egg-name does not work (for me?) on Heroku and no, Heroku does not handle submodules :(
I suggest you to have a link to virtualenv (you use it, right !?) bin folder inside base project folder.