If Hyatt is still offering the 2 nights anywhere in the world cc offer, I'd grab that. Just returned from doing our own Ireland London trip and found the Andaz Liverpool street to be excellent. If both of you get it, that would be four nights taken care of and the card provides platinum status at Hyatt.

The other chains have more availability in terms of the number of hotels, but I like Hyatts offer of nights instead of a set number of points.