I would suggest a combo of two "international" sims.
For example
PrePaidGSM: WorldSIM has incoming calls for free in 3 of your 4 countries.
and
http://www.maxroam.com/Info/Rates.aspx?cur=EUR covers the other one.
You would receive calls for free.
Try to search here, you could find a nice combination.
PrePaidGSM.net: International GSM Operators