i'm not sure you want to buy a coop with an attached run. That's a mighty small run, unless you plan on letting them free range during the day. With the area you're going to be using, it would be easy to add chain link fencing panels on the remaining side, as others have mentioned. Then put hardware cloth or corrugated roof panels over the top.
i'm not very handy, and the thought of building a coop was beyond me. But i can do little things, modifications. The first coop i bought was the chick-n-barn. It was about $325. But i needed to add a floor, and then raised it on posts about 3 feet to create more room for my girls. It's pretty flimsy, but we don't get too harsh a winter here.
After that, the rest of my coops are kid's wooden playhouses from craigslist, Lowes, or ToysRUs. Much better construction that most of the prefab chicken coops you can buy on Amazon or ebay, or in feed stores. You still need to add a floor, 1/2" hardware cloth over the windows, latches on the door, roosts if you have birds that perch at night, and prefab next boxes. i did score an incredible playhouse on craigslist built by a contractor for his kids for only $400. It was built like a regular house, with flooring, dual pane windows, the whole nine yards. That is my favorite coop.
Here is the last playhouse i bought, from ToysRUs: http://www.toysrus.com/product/index.jsp?productId=4400914 It's only $250 and free shipping. i was using for my ducks until just recently when i moved them out to a bigger coop and pen. It has a large back window that needs to be covered in the 1/2" hardware cloth, and then for winter you would want to cover it in plastic, and you would need to add a floor. But it's fairly sturdy and would easily house 4-6 standard size chickens.
i'm not very handy, and the thought of building a coop was beyond me. But i can do little things, modifications. The first coop i bought was the chick-n-barn. It was about $325. But i needed to add a floor, and then raised it on posts about 3 feet to create more room for my girls. It's pretty flimsy, but we don't get too harsh a winter here.
After that, the rest of my coops are kid's wooden playhouses from craigslist, Lowes, or ToysRUs. Much better construction that most of the prefab chicken coops you can buy on Amazon or ebay, or in feed stores. You still need to add a floor, 1/2" hardware cloth over the windows, latches on the door, roosts if you have birds that perch at night, and prefab next boxes. i did score an incredible playhouse on craigslist built by a contractor for his kids for only $400. It was built like a regular house, with flooring, dual pane windows, the whole nine yards. That is my favorite coop.

Here is the last playhouse i bought, from ToysRUs: http://www.toysrus.com/product/index.jsp?productId=4400914 It's only $250 and free shipping. i was using for my ducks until just recently when i moved them out to a bigger coop and pen. It has a large back window that needs to be covered in the 1/2" hardware cloth, and then for winter you would want to cover it in plastic, and you would need to add a floor. But it's fairly sturdy and would easily house 4-6 standard size chickens.