Unlocked Iphones/ International cell services?

I'm going to Germany in September for ten months. I would like to take an Iphone that I will get set up with a carrier over in Germany because I feel Iphones will be more expensive to buy over there. I was wondering if anyone knew which carrier I should buy for getting it unlocked or even if an unlocked Iphone will work while I'm there. I don't want to get an Iphone there and have it not work while I'm there. It would be a big waste of money that I don't really have.

Try to have your phone unlock so that you will be able to use your phone to any carrier. Also you can use it to other country's local carrier. Try the unlock process here at http://jailbreakhome.com/iphone-factory-unlock.