I am using the Sea Horse brand hard case. TSA approved. Custom fit your goodies how you like. $$ less than most cases. Inside i have P3P, two batteries, remote, 8 props. Charger, tablet, sd cards and usb adapter, 4 propguards ans the little baggie with spare cushions that came with aircraft. Not to mention a full printed out booklet of owners manual. Im very pleased with the set up.I've had my own P3P in GPC's Hard Case for 3 weeks now and have been doing a lot of traveling with it, really like it.
The best news is that we just received in the second wave of this case and they are now IN STOCK and ready to ship. They can be ordered on our website here: https://www.advexure.com/store/dji-phantom-3-case/
If you have any specific questions about the case feel free to give me a holler as mine has gone everyone I've gone for the past few weeks and would be more than happy to answer any questions you may have.