I suggest the best Gopro you can afford with a cheap eBay brushless gimbal. You can probably get by with some of the GoPro clones but I have no direct experience with them
Does your P1 have the 7th ch control installed on the rear of the remote? If so, you should be able to hook-up and use pitch control for the gimbal.
Now, if you want FPV or live video - that will require a TX/RX setup like Boscam 5.8Ghz, cables form your camera, etc.
Be aware you can’t use 2.4Ghz or wifi video connection on P1 as it’s been reported to interfere with the remote controller.