The only difference in the syllabus is that INT includes the audit of performance information in the public sector (see Chapter 31 of our notes) whereas UK includes auditing aspects of insolvency (see Chapter 32 of our notes).
I suggest you go with what is either more familiar to you or more relevant – e.g. if you studied LW-ENG (or GLO) you presumably studied insolvency – so the topic in AAA-UK will not be entirely new. But if you are already encountering audit clients in the public sector, or likely to in the future, AoPI in AAA-INT might be helpful (also in meeting PER objectives).