Noob comment here. I took the advice regarding wide views, and ordered three varifocals plus four fixed 6mm to save some money. I have not wished for wider from the 6mm cams... and all the varifocals are zoomed in tighter than this FOV. I might miss a bit of the yard here or there, but there are better recognition possibilities at all the key areas which must be traversed if up to mischief.
The alternative is to wait until your varifocals turn up, then decide what to order for your fixed cams. If I had more time for installation before I went overseas, this is what I would have done.
Cheers, Steve