The number one issue most people make when installing cameras is hoping to cover large areas with one camera AND hoping to get an identifying shot at the same time. What I would say is you have to choose between two tradeoffs.
1) Wide shots will get lots of context info, but will miss the identifying info
2) Tight shots will get the identifying info, but without the context.
So, what to do? Saturate the area with a balanced mix of overview and detail cams. You have a great pinch point at the gate. He walked through that area multiple times. Unless he chooses to jump the fence at the other end, you will get him every time if you have a straight on shot, with a tight FOV on the gate area.
You can go about this two ways:
1) Vandal dome mounted on the wall right inside the gate opening. This will be a cheaper way because you can probably use a fixed lens. Make sure that you get one with IR built in so you can get the night shot. WDR may not be needed because your subject will most likely be the majority of your view.
2) Box cam with long lens (or a bullet if you can find a long enough lens built in) mounted across the yard from the gate. You will need the long lenses to zoom into the gate area. In addition to that, you also will need a light source to illuminate the gate area, because it is likely that a box cam won't have IR and integrated IR in a bullet will not reach that far. Don't forget that WDR will be very important here if you cannot get the FOV down to just the subject.
At this point, you now have both the overview and detail shot at the pinch point. Obviously, if you have other points of entry, you will need to cover those as well.
On to the recording side of things. I would highly recommend looking into some Dahua IP cams and an NVR. There are quite a few good dealers here in the US, but I recommend Sean at Nelly's Security. Dahua makes a plug and play NVR that will simplify the install. Sean also offers great tech support and manuals to help getting the web feeds going. You may not end up needing to pay someone labor, which you can spend on better cams.
I highly recommend the 3MP vandal dome for your detail cams. 3MP Link
For the overview, you can use the same 3MP, but this 1.3MP will do fine. 1.3MP Link
All that said, I don't work for Sean or Nelly's in any way. I have purchased from him on many occasions and find his company a very valuable asset. I wouldn't hesitate buying from him.