Lynnie2002,
Though this isn't my first time staying off-property, it will be my first at Marriott Grand Vista. I've been checking it out as well. I have not as yet come across a property map. Perhaps if you call the resort, they will mail you one.
From what I've learned, supposedly buildings 80 and 81 are around the main pool and can get noisy. Buildings 97 & 98 are near a second, "quiet" pool. The Marriott website allows you to choose a view based on what floor level you are rather than room views. I don't know if it is something you can change or if you have to book a new reservation to do so.
If you are not trading in via a timeshare, I would suggest rechecking rates for your time period. I originally booked at a supersaver rate and the AAA rate was higher. A few days ago I checked just for fun and was pleasantly surprised to see the AAA rate lower. I rebooked without a problem.
If you do come across a property map online, let me know!
Sharon