I used to live in Cayman and still travel there a lot, we used to have lots of flights booked with 6+ month returns. You can join First Caribbean and get a BA VISA card but we never bothered as when you are there you end up flying mainly to miami. Cayman Airways are the better option for MIA flights as the AA ones are often Late, also if you miss a connection and are travelling on to GCM Cayman Airways will normally switch flights for you free. If you open a Butterfield Bank account in cayman and get the gold card you can easily save up miles for Cayman Airways.

PM me if you like, I have loads of tips for living there, but easier in a phone call.

Joejet