Ok, seems that this was a difficult question.
Moeller Belgium brought me in contact with their Germany friends so I know now that an Easy can be connected to a PS4-201 through a XC200.
Both PS4-201 and XC200 can communicate over Suconet and the XC200 can also talk to an Easy over Easynet.
This isn't a cheap solution (+1000 euro) but I'm afraid I have no other choice.
At least now I can say I need 2 CPU's and 8 Easy's/MFD's to get my domotica running.
An other fact is that I also need 3 softwareprograms: Easysoft, Sucosoft, CoDeSys to get this things working. On the other hand, all of them can be programmed by Ethernet and have an OPC-server.
I think to program only one CPU (PS4-201 or XC200) and use the other and the Easy's as slaves.
All suggestions are still welcome.
Danny