Here some German pages where you can get your stuff.
I´m actually in Germany so I use/used them and they are all doing fine:
http://www.asmc.de/en (English Site)
http://www.sturm-miltec.de/ (Pretty huge was already there and also english site although it´s a retailer so you should order as a club or business)
www.begadi.com (There are also airsoft guns but you better never import weapons nor relevant weapon parts)
http://www.armyonlinestore.com/ (good stuff but looks like it´s in German only but maybe you find a button to switch language)
http://www.troph-e-shop.com/ (nice shop and also in English)
So if you don´t find the German uniforms or parts I guess you won´t find it anywhere.