"which of course will render the 1401 useless", Ok but it is misbehaving, and you want to replace it. The "boat" style array you have is , sorry, yes, long in the tooth. I had 3 (ws-1000,1001,1002) same external array.
I now have the try wing array , same as that in the ws-2902/ws-2000 packages (I do find it better)
I see you are opting to not have a new display console , is the display console important to you?
There are quite a few that view the ObserverIP as antiquated, I never had one. I just bought a WS-2000 (2 years ago).
Can you, maybe outline what you want the new system to do? Read what, post to where (weather sites), etc. There are a bunch more options now.