Fox proofing - use electric poultry netting, preferably mains powered. Ous has worked well, we haven't had a fox attack (yet) in the last 4 years. Although fox visits and checks out all three enclosures (seen recently in the fresh snow).
We got our sheds built by local sawmill and put together ourselves on site (we added the perches and pophole ourselves, otherwise cost too much). They are screwed together, so we can take them apart between batches of layers (every three years or so) and clean out properly. That way we can also move them into/out of places our little tractor cant get to. We use plastic boxes for nest boxes inside the sheds, seem to have less problems with red mite that way. But need to get inside for emptying (I dont mind).
If you want to do meat birds, get day olds and rear for about 12 weeks, for layers hybrids like Black Rocks are great. I have now got a Maran cockerel on RIRs and Lt Sxs hens, their offspring lays well, and we eat the cockerels ourselves, not enough meat on breast for roasting, you really would do better with a meatbird for that. But good leg meat, especially for curries.