uhh, wouldn't you also want a number of simultaneous incoming calls? I mean if you get your service up and running, get everybody memorize your phone number and then incoming calls are greeted w/ busy signals. That wouldn't be good for suicidal situations, right ? :)

Google Voice is good for a single call but I don't know if it has call distribution. What you need sounds like a PBX w/ call hunt-group feature.

I think there are grants and financial aids from Western non-profits and NGOs available for things like what you're proposing. perhaps you can post request for helps in those forums also.