I carry the RA9T in my R9, but use Federal Tactical in my Sig 239 .40.
The reason I use RA9T is that it is standard pressure and tests as well as +P rounds in lab testing.
There is nothing illegal about JHP ammo for someone who is not a police officer (police officers are civilians - I was an Army MP, so I know). In NJ, it is not legal to use JHP for carry if you are not a police officer, but what you use in your home is up to you. Since pretty much no one can carry in NJ legally anyhow, it makes little difference.
As for civil liability, I am aware of no case in which this was a problem. As someone else said, if the police carry it, we are well advised to as well. No matter what you do, you can be sued. If you use ball ammo and it over penetrates, you will be sued. If you use JHP ammo and it does it's job, you will be sued. Face it, if you fire your pistol in self defense legally, you're very likely to be sued. Pick the ammo that does the best job in your pistol and for your needs.