David,
Yes, I think designing the stalls as blocks would work well. You can assign those blocks to amenity reference notes and even use our F/X Site copy along line or polyline to string them along your design as needed. You'd have 2 blocks - 1 for a regular space and 1 for an ADA space (which can include the ADA markings - we have some readily available under Plan graphics/handicapped). You can then run a schedule that counts them, or use highlight object.
Save Your Blocks Into Our System
Amenity (Object) Reference Notes
Copy Site Objects Along a Path
-Amanda