I have a fantastic trip for you with both beach & city. Take a nice 10 or 11 day trip and do Greece & Turkey:
5 nights at the Blue Palace in Elounda, Crete
5 or 6 nights at the W in Istanbul
These are both amazing properties in fantastic places and you have enough SPG points for both.
If you're looking for a WOW vacation at WOW properties, this is definitely a good idea.
Enjoy your trip!