I would say it would be better to network for volunteers in your area that would care for the cats. It is better to have a cat lover as a caretaker. Someone that is civic minded and does not mind donating their time to this worthy cause than to pay somebody.
|Feral eat cat food in back garden a photo by Sgolis|
Know that it hard to be solely responsible for a colony of cats and it is better to know other civic minded people that will share in the duties of feeding the cats and chipping in for the food and or medical costs. My husband helps me and I have two neighbors that donate their time and help the costs for food, spays and neuters, or vaccines for the cats.
Here is a post that I published that may be of interest to you: What it means to be a Feral Cat Colony Caretaker