Honestly, best bet if you want something that will last you a couple of years will be to get something in the 900-1200 euro range...
Coming from an American perspective I don't know exactly how much things cost in Europe, but guessing how things in USA cost 1200 for a decent gaming PC thats my guess for you.
Personally I wouldn't get an AMD graphics card because those do not have the higher processing rates as NVidia and usually come with lower dedicated memory. Something I came across on FPSLeague (the comp league for Soldier Front 2) was somebody looking for something similar to you. Another player recommended that they just buy the individual parts and build it themselves.
http://pcpartpicker.com/p/pCkbYJ is a list of parts that will last you a good 2-3 years and still be able to keep up with modern gaming technologies. Easily be able to do high graphics on most games and in 2-3 years still be on medium-high graphics. As well, if you build it yourself, it will be easy to upgrade in the future, saving you a LOT of money down the line.