I'll comment on which scope is better. I have many Nikon Monarch and pre-monarch scopes and they have NEVER failed me. They are bright, clear, sharp, and track very well. I once had my Nikon 3.5x-10x-50mm mounted on my Browning A-Bolt Stainless Stalker in .270 Winchester. I was walking down a steep slope and the rifle fell out of my hands. The gun (with scope) slided down about 10 feet or so, going over rocks, etc. I though the scope would be damaged, but it wasn't. In fact, I took it back to camp and shot it. Guess what? It held it's zero! Wow, boy was I surprised. So do I recommend them? Yes. I own about 7 of them and couldn't be happier.
As for the Weaver GS, I have only used them at the range and their optics seem good, and their tracking is excellent. No long term use, nor do I own one, but from my limited experience, the GS scopes are very good. The one thing I don't like about them is that they have a very short eye relief. I know that you are concerned with FOV, but I'm more concerned with eye relief, especially on harder kicking rifles.
I don't think you can go wrong with either one, but from personal experience, I would recommend the Nikon Monarch.
Zachary