Ditto on the Premier 1 fencing . . . we love it, and it is relatively easy to move, and looks decent. You do have to move it every three to 4 days when the grass is growing fast - but that can be just a foot one way or another. Keeps stray dogs off of the chickens until you have time to deal with them, and protects from coyotes and silly chickens going where they are not supposed to. Important to get a good quality charger though -- not feed store brand cheap -- otherwise you'll have problems. We are building permanent non electric fences as we have time / money, but we love being able to move the birds to a new fresh location . . .
As for hawks -- a good rooster is great! He'll warn them, they'll all dash for cover . . . I have my chickens in an orchard right now so they have ample cover from hawks and we haven't lost any yet. if you don't have low trees or bushes, you'd have to make some shelters to scatter around, especially if they are far from the farm buildings. There are some hawk deterrents but I haven't used any . . . . my geese seem to help keep the smaller hawks intimidated, but don't know that an eagle would care . . .