Various questions regarding action cams (Allowed? If yes, which ones?)

Hello MotorTalk-Forum, I want to start riding a motorcycle soon and of course also make some nice shots. First of all there is confusion with me, if it is now allowed to film with an action cam while driving. Some sources claim it is allowed and others claim the opposite. Another question is of course what kind of cam you should buy. At the moment I tend to a GoPro Hero 5 or GoPro Hero 5 session (possibly also with Gimbal) what you know for alternatives that you could recommend to me. I can spend around 400-600€. Sincerely Lenny