I'll answer you in English, so at least everybody can benefit from this...
I have done my training at the BAS - Belgian Aviation School (now called SFA - Sabena Flight Academy) a few years ago.
I know the costs at the SFA are pritty high, but getting all your licenses will be very expensive anyway, even if you try to get hold of them all on yourself.
With the SFA licenses at least you're pritty sure of a smooth carrier at Sabena, whereas with other options you might not have a change to join us at all!
Yes, there is a big need for pilots in Europe, but someone who has just finished training is not much wanted, not even at present rates of growth. This goes not only for Sabena, but also for every other company I know. However, Sabena has remarkable low entry criteria for pilots comming from the SFA. You become a first officer on A320 with as few as 350 hrs of total flying experience!
Also keep in mind that FAA licenses are not validated in JAA licenses. You'll have to pass (al least) all the exams again. If you add to this some extra flight training because of the fact that you'll most likely not find the same plane you used to fly in the States, the very different flying environment and the time between your checkrides and you'll easily see that a low cost solution might be very expensive after all.
In a nutshell: I can not give you much more advise then this:
Both options are available and I can give you several exemples of boys (and girls) who made it. On the other hand I can also tell you about bad experiences people had with both of these methods.
In general you might say that the SFA is somewhat more expensive, but is in general a safer and much faster way into the cockpit.
I hope this insight view helped you somewhat.
I have to go to bed now, because tomorrow I have to wake up very early not to mis my flights...