Stables with horses supply, power & lighting etc..

Hi all, I have never had to look into a job like this before but I have had an enquiry from a customer who is having a supply brought from the road to edge of his fields / property by the dno and he has to supply cabinet etc.. at a great cost for the mains !

I have to look at a run of around 45 mtrs of s.w.a in a trench to stables, into a small consumer unit at one end of stables where horses will not be but just a storage area. Couple of sockets there adjacent to board, and all light switches there too out the way. They want lighting above the two stables where horses are resident and also floods front and rear outside plus a small sub out to another shed / tack room across the yard around 24 mtrs away. I am thinking a lot of armoured plus maybe a bit of conduit in stables to lights high level etc.. and rcbo cover but would 30mA be alright with livestock ?

Also if board was TT'd with a rod outside away from stables by around 3 mtrs or more is that likely something you would go for ? Only issue I can see is that all around are other fenced fields that have electric fencing so is that likely an issue with the rod and fence earthing rods etc.. ?? never done something like this before.

Also what protection / isolation device at start of mains to the main board?
A time delayed RCD S type at 100mA or similar as thinking just a switch fuse wont be good enough.

Thanks for any experienced thoughts.