Welcome. I am located in the East End (Hamptons). I did purchase my coop from Green Chicken Coop because after extensive research, I found them to match my needs for both the run and the coop. You can also look at Sheds Unlimited, Horizon Products, My Pet Chicken, EZ Clean Coops, and your local Agway dealer. There are many on line distributor like Strombergs, My Pet Chicken, Meyer Hatchery,Murray McMurray, Chickens For Backyard, Randall-Burkey, to name a few. The prices vary and some are free shipping and some have specials.
In terms of the chicks, I ordered from the Talmadge Farms Agway in Riverhead because they have chicks available now at this early time of the year. They also have a great selection of coops, but the prices are high so you need to do your homework.
In terms of corn-free and soy-free feed, be careful. You may want to contact Nutreena, Purina, and other feed manufacturers to ensure you are not compromising you child's health. There are a lot of organic feed suppliers out their, but the shipping cost is high. Contact Talmadge Farms as their staff is incredibly knowledgeable. Also, google soy-free and corn-free chicken feed and see what comes up.
Good luck. If you need more help, just ask.