For the games you listed even a 7870 is overkill. Also for the games you listed you
definitely want to go with Intel because those games rely on individual core performance far more than multi-threaded performance. Core-for-core Intel destroys AMD.
Anyway lets start from scratch...you mentioned a budget of 700-800 EU and parts from either Germany or Sweden.
Since I have no clue of a good site from Germany,
purely for price-checking purposes I used
Komplett.se which is apparently a renowned Swedish PC part site.
CPU -
Intel Core i5 3570K
Mobo -
Asus P8Z77-V LX
RAM -
Corsair Vengeance 8GB LP
Cooler -
Hyper 212 EVO
GPU -
Gigabite GTX660
PSU -
XFX Core 550w
Case -
Fractal Design Arc Midi
Total: 6614 SEK = ~$764 EUR
Sorry if the actual price after shipping is way off, I dunno if the above price even includes VAT because I can't read Swedish -_-
I need to know whether the above build is even remotely fitting in your budget or whether the parts are available wherever you're buying them from. If you can give a link or two to your preferred German/Swedish stores then I can check for parts from there.
You don't have to get those specific parts, there's quite a lot of flexibility to cut some corners and get that price down even further. I'm just showing you the "standard" sort of gaming build we recommend on these forums and since most requests are from US, I'm not familiar with EU prices/stores.