I would like to give them as much space as I can safely afford to start off with
Any ideas are appreciated
Your area/region may come into play as in what type of animals you've got about you. If in town or country sort of thing. In towns your really only keeping out dogs and skunks, few others maybe but loose dogs is a big thing.
Electric poultry netting is a really good option but then if your in a heavy winter area it may not be used all year. If it can be used all year that's my favorite. We use 164' of 4ft poultry netting, 4 extra heavy duty posts to aid in keeping tight with hotgate and P5 charger. Makes for over 40x40 run that's portable and cost all told $350 range. We went with the P5 as it can be moved far away from outlets and run off battery. Big area to move around on.
In general the coop is your biggest protection and to work must be locked up every night. That takes care of a lot of predator problems right there. Coops get all holes/vents covered with 1/2 inch hardware cloth. The run itself can be covered with 2x4 welded wire. Smaller and square looks nice but hard to find and bit pricey. 2x4 14 gauge is $36 a 4x50 roll at your area box store like Lowes. Cover the top of run too. Without electric critters climb so a top is needed. Think raccoon. Many digging predators and in towns your biggest problem will be skunks. Large skunks do indeed dig right under the run wall and kill birds. An apron stops all that. I use the same 2x4 welded wire and cut lengths then in half. 18-24 inches flat out from run wall is all it needs to be. Either stake it of lift sod and lay sod on top of it. Two side are cut longer to make a complete perimeter. Again, without electric many animals dig under.
I don't know how large your plan is getting into chickens. If your starting out you can always build a smaller pen that's covered with wire or roof and plan to use that each year as the grow out pen and small coop. This keeps costs down and if you have in mind it's yearly reuse puts it all in perspective. I use mine as the breeder pen in spring, gather only those eggs to hatch then put those birds back with flock when done- first batch out of brooder and all others go right to that pen. Selection for keepers, sale of culls and butchering of unwanted cockerels is all done from there. What's left is integrated into flock when 15 weeks or so. Forgot to say I use screws with fender or whatever cheapest box of washers to attach the welded wire to pen. Rock solid connection and can be taken off if need to readjust during build or reuse for another pen/project.
With a large pen and layer coop covering it is cost prohibitive. If you use electric strands off set from a fixed run or use poultry netting nothing will climb it. Full grown large fowl are rarely on hawks menu. Small birds need a cover for sure but hey, every day this past summer there was a large hawk on power line overlooking the fields for mice and vole. Not 200 yards from chickens with only 4ft electric netting for protection.
West Virginia doesn't get much snow at all. Had I known about pos/neg fencing prior to purchase would have gotten that but I still get a lot of snow...probably alright I didn't. In your area that type of fencing would work year round. It doesn't as readily ground out and loose power. It's a bit more cash but in your area can be the only run you use year round. The birds your raising are trained fast too. If they never flew over normal fence and electric is what they know they quickly learn not to be right next to it and never attempt to fly over as they like to fly to top of fence then down but they avoid the fence so it doesn't happen. At least with my 48". Quick search at Premier I only found a 42 inch. But the 100' length would make for a good run and they are portable. They've good customer suport, fidning products or answers is not an ordeal. If your coop is somewhat portable you can move it all 40 feet over for fresh forage. Or have the run offset around coop in rotation of compass. Around coop but mostly open on east, then in two weeks mostly run on south side, etc. In that way the grass and bugs have ample time to regrow. Animals can't dig under it as the bottom wire shocks them. Can't climb it. Coyote can jump it but like all animals are curious and will come inspect the fence, get shocked on nose while nosing about and never return. Wildlife is quickly trained to avoid it. Have I told you yet I love the poultry fencing? LOL
Here's a few quick links to get an idea and I'll let you be and let others chime in:
Gate, 100 ft fencing, charger kit with 100' wire to outlet= $375. It's not cheap but quick, easy, versatile and very effective on predators.