I looked at the pet tag thing but I wanted to have something that I didn't have to pay for monthly so I got one of these....
http://www.amazon.com/Real-Time-Por...?ie=UTF8&qid=1392236267&sr=8-1&keywords=tk102
All you need is a pay as you go sim card. I have it velcro'd to the bottom of my P2. I like it because its completely separate from the P2 systems, so worst case I have a P2 battery failure and the whole thing comes down, this separate GPS unit will still work...... assuming it survives the fall and I didn't fall into water
I understand the feeling about confidence and I agree with the other posts about watching all the videos. At the end of the day, the best you can do is educate yourself on the Phantom and try and do everything right, but you should always be willing to deal with the off chance you don't come home with your Phantom. I guess thats the price of having all the fun you can have with these things.
I recently took mine to Bora-Bora where I flew it out over the ocean, way up into the sky, and along the lagoon waters at a height of around 10 feet. Everything involved some risk, but it was really fun and the video footage was well worth it.
Educate + Get a GPS = Enjoy