[Ghostwhite]

You only need one pressure sensor.
I would connect both tanks together with an airline, this way you have equal pressure in both tanks and also if one compressor fails you still can fill both tanks.
You will be fine running a short piece of hose but it would create a few more possible leak areas.

Are you using both feed ports on your accuair manifold? Most likely you are running one tank into either side of the manifold(this would also join the tanks). If you join the tanks with one line and then run a line from one tank to one side of the manifold feed and then you can run your sensor off of the remaining manifold feed port. This could reduce max flow but not too greatly.