Before getting into a specific recommendation, here's some advice: Go ahead and hold reservations for whatever you are thinking of doing. It's easier to make three reservations and cancel two than to start to make plans only to discover your options are gone. Hawaii and Europe are popular redemption destinations; inventory can disappear or reappear suddenly. Call Marriott Reservations, explain you are making plans and will cancel two of the reservations in a short time. Ask that they not take the points out of your account or apply the cert for now. I actually did this in the past week, holding three different reservations for a few days until flights and schedules could be confirmed. It's not a problem to do this.

Since you are locked into Cat 8, I'd recommend the Paris Opera House Marriott. In addition to touring Paris and experiencing world class museums, restaurants, window shopping and people watching, you can do day trips to Versailles, Normandy Beach and London. You may even want to extend the trip slightly by staying near the airport both the night you get in and the night you leave - cheaper hotels - so as to have time to do all three, plus tour Paris, or by adding a couple days in London, Amsterdam or Brussels (awesome train rides) or Prague, Vienna or Rome (inexpensive fast flights) to the end of the trip.

Whatever you decide, you'll have a great trip to either place. Enjoy! Let us know what you decide and then how it goes.