the wifi part will be done by a couple of airport express stations that I am not using anymore. Airfoil is used to strem from the macbook to them.
Do you plan to use one Airport Express per Speaker? I'm asking, because I'm not sure you can stream to two devices at the same time.
then either the JBL Control 2PS or the Behringer B205D as active speakers.
I would choose JBL as they make the more reliable products. Another excellent option would be a used pair of Genelec 1029A which can be found relatively cheap. They sound very good, look good, have an all-aluminum enclosure, and a thread on the bottom allow them to be mounted on (microphone) stands.
There's also a matching subwoofer, which might be necessary depending on the size of the room and the type of music you want to play back.
As you seem to be from Germany: thomann.de is the best place to buy music equipment, such as the speakers you mentioned. They are the cheapest, ship fast, and are very fair when it comes to taking back stuff.