Quay Center is outside the pier area... and that would be a pretty long walk. Not sure if that outlet has shuttle service to/from the pier. Though I know Budget offers shuttle service to/from the airport... which is only about 10 minutes away.
If Budget won't shuttle you to/from the dock, go with Thrifty. We rented a Thrifty minivan at the airport (one day before cruise, one day after) and it was only $38.99 / day plus taxes. They shuttled us from the airport return to the dock, then picked us up at the dock on our return (that took a little longer as there were _9_ ships in port that day).