First, congratulations on your purchase. You'll have a whole lot of fun and you might even pick up a few frauleins with it!!
You will find that even with an automatic, you can easily do 140+ on the autobahn so don't worry too much about being left in the dust. But make sure you have good tires and brakes. Spend some time getting to know the car and its already great capabilities. And with the summer coming in Germany, you will want to have a nice ride to check out a whole bunch of fantastic places.
Check with the PX to see what they can order for you. I would assume that basic maintenace things are available (oil, filters, plugs, etc). There are a number of Corvette clubs in Germany and you might be able to hook up with one. Expect them in the larger cities like H-berg, Munich or even Frankfurt. There are some big clubs in England, Holland and Sweden. Try doing a Google search on "European Corvette Clubs" or something like that.
Some parts suppliers will ship to APO/FPO addresses (Summit Racing is one so checkout their website
www.summitracing.com ) They really don't show a lot of Corvette specific stuff, but you can always exchange e-mails. IF you need brake parts, try the Tire Rack
www.tirerack.com They also ship to APO/FPO addresses. Expect ship time from 4-10 weeks for stuff from CONUS.
As far as books, the Haynes and Chilton manuals are very basic and really don't get into the level of detail that a Helms manual does. Helms prints the factory service manuals for use by GM service techs and those are the ones to have. Go to
www.helminc.com to order one. They run about $100 but are worth their weight in gold, especially if the car has to be worked on by a technician that may not be familiar with the C4 systems.
If you have trouble getting stuff delivered directly to you, consider having a good friend or relative get the things you need and then have it shipped to you.
WhenI was young (many years ago!!) my folks and I lived up in Hanau. Graduated from high school in Frankfurt. Really enjoyed Germany and all that I saw in Europe. We got there just as the Wall was going up. Sure miss the beer!!

And thanks for serving your country!! You are very much appreciated by your fellow countrymen for all the sacrifices you make.
George
US Army 1967-1970
Viet Nam 68-69