Good rule of thumb is 4 square feet in the coop and 10 square feet in the run per bird. You're well above that, and your chickens will probably thank you! Having more space usually means you have less behaviors from your hens, they're happier and get along better when they're not crowded right on top of each other all the time.
Orpingtons are a good choice for backyard flocks, they're calm and docile and get along with people well. I advise folks who are new to chickens to try a few different breeds when they start, to see what they like best. Some folks like a flock that is all the same, I prefer a varied flock. Plus, having different breeds makes it so much easier to tell the birds apart. Honestly, one barred Rock or buff Orpington looks pretty much like another....same for most breeds. Also why I pitch Easter eggers, they have enough variation in color you can usually tell them apart. Plus, who doesn't like blue or green eggs?