I just got a new Phantom2. Is it possible to upgrade it to Vision+ spec or do I need to get a 3rd party gimbal and camera?

Buy the time you have added all the stuff to make a Vision +, it would have been cheaper to buy the + in the first place and have a fully integrated product out of the box.
You will need a 3 axis gimbal, GoPro, FPV kit including a monitor TX / RX and batteries, IOSD Mini, and the PC or Ipad Ground Station. And with all that you still will not be able to control the camera whist in the air.

Yes it is possible. However the camera/gimbal assembly for the Vision + is almost $700 by it's self. The Wi-Fi unit is $190.00 That is almost the cost of a brand new Phantom 2 Vision+.  I would go for a new aircraft.

momochi Posted at 2014-12-29 23:05
Yes it is possible. However the camera/gimbal assembly for the Vision + is almost $700 by it's self. ...

Where do you see those prices - DJI don't appear to be selling the parts unless I'm being a bit blind.

Crozby Posted at 2014-12-30 05:22
Where do you see those prices - DJI don't appear to be selling the parts unless I'm being a bit bl ...

Ebay and Amazon from authorized dealers.

http://1uas.com/Phantom2VisionPlus-Parts

They are DJI authorized dealer

Awesome. Thanks dudes.