Hi,
Standard SAP paym.methods in both countries seems to use RFFOM100 which is for MT100 format. There is MT100 format in PMW as well. Either one could be a starting point. Keep in mind that classic RFF* payment programs are not officially supported by SAP anymore and PMW is the tool for the future delivery of payment file formats by SAP.
So why don’t you ask your banks which formats they accept first?
Regards