No, the voltage is what matters, the screen will only draw as much current as is required. It would be good practise however to put a fuse on the positive power line to the screen for say 1.5A just as a precaution.
PC PSU's dont have any over voltage protection (prove me wrong, please!) as I found out when my PC PSU blew.
If you wanted to add over voltage, you would need to look at building some circuits to do it.