We are discussing this issue in that thread (as fas as offshore banks in Belize are concerned): "invalid1c/forum/f16/need-offshore-bank-account-belize-anyone-has-list-banks-there-8668/"
Check it out; your question about IBAN/ SWIFT is answered there. And by the way: the IBAN-System is a seperate EU-standart (only SWIFT works worldwide).
So, from my point of view, it can´t be the question, which destination is better for banking (Belize or Cyprus). It may be more important to find out by yourself, what is more convenient for you or/and your clients.
But my prior question would be: are there any restrictions for Americans to open a (corporate) bank account in Cyprus ? Admin, what is your experience ? As we all know, US citizens can´t do so in Switzerland anymore ....