Here's a quick overview about power systems and countries:

http://en.wikipedia.org/wiki/Mains_power_systems

As long as your power supply has a switch for 110/230V or 110/220V you should be on the safe side. Otherwise you may need need to look for a new power supply in Germany.

To get a clue about german prices for pc parts you can check out this quite cheap site: http://www.litec-computer.de/PC-Komponenten:::554.html

About flight security I don't know...