The buildings that are closest to the new pool area are numbers 79 and 84 (they flank the pool area) but I don't know the names of these buildings. If you plan to call the resort to request a location - I'd strongly suggest that you do that a week or two before your arrival date - they'll be able to identify location by either name or number.
Grande Vista is a moderately large resort with most activities located at or near the original pool area/reservation center. I think that, regardless of which building you're in, its an easy walk to the center of activities from anywhere in the resort. There are additional, though much smaller, pools located near the buildings that are furthest away from the main pools. There's a full service restaurant on site - Nick's - located at the golf club house area in addition to the Copa Loca bar and grill, the pizza express and the resort store. Lot's of activities including a climbing wall on the beach in front of the original pool area.
I think that the older main pool is the larger of the two and there is a lap pool in that area, too. Also a sauna and a few hot tubs. The newer main pool is rectangular and, like the other pool, has a small waterfall cascading into it. The 'special' feature of this pool area is the separate pool that has some childrens' features - a couple of small towers with water guns, for one. There used to be a volleyball net in that pool, but it wasn't in place for our last visit.
The resort was renovating the older villas when we were there early this year, but I don't know if they've finished yet. We were in a three-bedroom villa in the building next to the original main pool that includes the reservation desk. It wasn't yet renovated but quite nice anyway.
Finally, there is an older map at the TUG website (it doesn't include all of the new buildings that are along the 'other side' of the lake from the check-in/activities area. It appears to be a scanned map and is hard to read, but if you are a TUG member you can go to the reviews section and find Grande Vista in the Orlando list. When the review page comes up look on the left for the resort picture. Click on the text link View All Images. The map is one of the images you'll see there.
Dick Taylor
The original