the holes are predrilled and come with the screw connectors. I use these to build my runs and have had Javelina and bob cats bounce off the welded wire attached to the poles and not have had any issues. I watched a full size wild pig, waist high bounce off the pole and it did not move.We went back and forth between peaked coops and the flat topped one. The flat topped one is slightly larger and we're getting a good deal on it. We don't get heavy snow here. The entire coop will be encased in 1/4" hardware cloth, including under the tarp, water can't collapse it with the hardware cloth under it.
The henhouse opens up on two sides and the ceiling/top comes off. Does it need more ventilation than that? We figured we'd leave it opened up like that most of the year.
I worked out the costs of the connectors at that site, I think it came out to about $125. That's not bad but custom drilling all the holes and adding bolts and making sure everything lines up correctly, etc. sounds like an expensive nightmare. I'd rather buy it all already done.
We considered a hoop coop. Delivery costs on the cattle panels put it out of our budget.
I love the screw-in trampoline anchors. I don't know if those would work with the caliche here but I'd like to give those a try in addition to some above-ground anchoring.