The listed maximum is 12V
Then that is what you have to use, go over that limit and all bets are off.
You need a regulator to take the voltage down but you need a few volts higher than you are regulating down to. Is it specified to run off 9V? If so then use a 9V regulator, standard ones can cope with 1 amp. You need the current to be able to work out how much power you are dissipating and hence the heat sink requirement.
BTW you know voltage regulators shut themselves down on over current
That is only over current for the regulator of course not the device.