See if this message helps at all:
http://aspn.activestate.com/ASPN/Mail/Message/1063891
You can set your proxy info in env vars and it *should* work.
You only need pass/user if it's an auth proxy. If that doesn't work, I'll dig up the instructions for installing modules locally. Although PPM is initially setup with AS only repositories, there are *many* others you can use in addition. I use 7 or 8 just to get the latest and greatest versions of some of my favorite modules.
~Charlie