I'm also in Media, PA with four chickens. We buy feed/hay from Tobin's Feed and Seed on Route 252. They have organic feed which is a little more, but it's open good hours and have never had anything we couldn't find there.
Also - another thought, the Ace Hardware store in Aston purchases chicks annually - if you go to the building behind the Ace Hardware you can ask at the equipment desk and he'll tell you when they get them. I think you have to pre-order but if you are starting a new coop, it's a good place to get chicks. Not sure if you get them sexed or not, in which case you'll have to probably deal with the males after it becomes obvious.
If I think of any other local tips I'll let you know!