Eb,
Your biggest mitzvah would probably be to LET those guys be protectors and allow several homeless folks to help you plan/prepare. You'd benefit from their insights and have a much easier time of it starting off as a pet than if you try to swim uphill and carve your own path.

Giving invisible people a chance to be useful in a way that really IS useful is a very kind thing. That's where the Good Deed is.

**
Your shelter system sounds so much better than the arrangements I've heard from my friends who have used services in their area.