Then I'd grab the 555m.
Do you have a link to the site, google will translate for me. Do you know any other sites in Germany? Any place that sells Sager/Clevo, Asus, MSI laptops?
You might understand this even without translator. These are my best results so far. Preconfigured builds are sometimes cheaper, but then they don't have good graphics cards.
http://www.one.de/shop/product_info.php?cPath=203&action=config&products_id=5598&grt=1&tar=19&nav=off http://www.notebookguru.de/de/Notebooks/Guru-ICE-SB-config.html
http://www.one.de/shop/product_info.php?cPath=203&action=config&products_id=4914&grt=1&tar=19&nav=off http://www.notebookguru.de/de/Notebooks/Guru-FIRE-SB-config.html
If someone finds a good offer for an ~15" laptop with 8GB RAM and a good* graphics card, please share.
* Since I want to keep the laptop for some years, it should be in the higher range.