Have you considered a Panama Canal cruise (LA to Florida or Florida to LA)? That would definitely cover your 14 days.
If you are looking at two seven day cruises, it does not necessarily have to be a B2B on the same ship. You could switch ships with a day between the cruises.
I would suggest one of your cruises go to Aruba, Bonaire and Curaçao.
Best pricing would be in January or February.