Maybe www.alleycat.org can give you a local contact. There is for sure somebody in your town who supports rescue groups or TNR . By joining Alley Cat Allies or some local feral cat program you will have easier to get some food donations. There is lot of stores that donate almost...
The feral clinic in our area which gets money from our city and from charity takes lot of an cat's ear. And it is often cut badly, like the ear on your picture. Male cats with thicker ears bleed a lot. Explanation why they have to take that much - people would bring owned cats...
I want to buy on line vaccines for my feral cats too. One place where I have them fixed offers just spay/neuter surgery and rabies. The other place let care takers buy FeLv test ( $ 10 ) and FVRCP and chlamydia for $8. I would prefer to administer myself MLV ...