and about the cards 560 or 570 they will not do me any fps downfall or bottleneck in games like FAR CRY 3 or Battlefield 3
because now i`m playing not in the highest level and it`s runs very good
By on par he meant not too much bottleneck. Anything above that will risk to suffer from more bottleneck by the CPU and thus not be worth the extra money. So your sweet spot is probably the 560 or 570 or 650Ti or 660 or any other similar cards but I don't advise going above that.
And when you say never mind the PSU, I don't agree it's very important so make sure it will support your new card and not damage it. Unless you meant by that you already have a powerful high end PSU.