You are looking at the right route. Fatshark goggles have the vTX inside it and you can share the output with the provided cable to a monitor.
7" Monitor options are a plenty BUT make sure it is one that specifically doesn't go to blue screen mode when signal levels drop... really cheap ones on ebay can be like. Better to see through the static than stare at a blue screen!!
Ground station is a bit of an unknown. The full 2.4ghz Datalink will, I am sure, work via the Canbus port on the leg right out the box now so you could could get this. It is pretty bulky to add to a Phantom in its full form though. If they have integrated a BTU into the board already (and just not activated it via firmware yet) then that is one less thing needed but from looking images of the main board i doubt that is the case.
Personally I'd get Fatshark Predator v2 kit so you have the video transmitter, goggles, video reciever... then get the monitor.
With all of this in place you can at least have fun with FPV and get used to it until January. By then you will know what is required for the ground station.
DJI have taught us plenty of lessons on 'rushing in' with purchases so patience
is wise here.... people went the PMUv2 route when the Zenmuse came out and then DJI made that an un-needed mod with the upgrade board... the Vision is another example where patience gets you a much more versitile craft in the Phantom 2 (just my opinion).
I am sure we will all have leaked info within a few weeks of what the Groundstation will give you.
I suspect there will be a 'lightweight' version of the 2.4g Datalink specific for the Phantom (like the iOSD mini was a light weight version of the iOSD Mk2). Smaller, lighter but with slightly less features than the bigger version. More money to DJI by making people think they will have a ground station capable machine at purchase, only to spring new hardware needs on you afterward (yes i am a synic but business is business and DJI know how to make money)