wondering if anyone here can help me out with some sim card info for belgium & the netherlands....

during my regular trips to the hague & brussels, i have never stayed for more than a day or two....plus, all these trips have been work related so i have never bothered getting a local sim there....next month i will be there for a personal trip & for a period of 12 days....so i need to get a sim for both places....i was looking for a sim that i can use with my iphone (unlocked)....what is most important to me is data use....i don't care what the calls & sms cost since i will rarely use that....but i will require data usage all the time....

i would prefer to get a different sim for both amsterdam & brussels since i don't want to deal with roaming charges....does anyone here know which sim to get????