The chicken area, unless you're planning on any unsupervised free range time in the larger fenced portion of your property.The chicken area or the property?
Chicken run + main coop + mini-coop take up an area approximately 8 feet wide by 26 feet long. So I guess the fence would need to encompass an area several feet larger than that in each dimension.
I just really like chain link for its ease of workability, it's indestructible, and price. The posts make it easy to run hot wire too.