havent actually sold any beats, but at my 9-5 i used to deal with a few international transactions for services, which is basically the same thing.
so heres my 2 cents for what its worth:
first and foremost, whether its local of international, get yourself a contract. get a lawyer if you must,.... but do get something in writing. even if its as simple as " i foreign dude would liek to buy your beat".
then you can have them do a wire transfer, either bank to bank or thru something like western union. atleast then its solid, its gone thru the banking system.
i'm pretty hazy on the whole paypal e money thing as i have no experience withthose kinds of payments.
i agree on the check thing being not ideal,... unless you dont have to send them the beat until their check clears. and international checks can take a while, sometimes up to 10 working days.