I would purchase a standard room and take my chances on the upgrade. I could probably count on the fingers of one hand the number of times I was not upgraded at a full-service Marriott. (I'm not talking about a suite here!)

The hotel is unlikely to sell all the executive-floor rooms, so they'll have one for you. They probably release them first-come/first-served, so if you arrive at a reasonable hour, you should get a decent room.

Last time I was there, I stayed in Room 1025, which I believe is the only room with a balcony facing out from the front of the hotel.

Bruce