When you make the reservation, the online tool will show you the options for both points and cash upgrades. The property can offer either or both.

As for getting a guaranteed building/floor, good luck with that. I suspect the owners will get first dibs on most requests. So you as a non-owner will most likely get what is left-over. And if there happens to be a room in the building/floor you want, you might be able to get it. If there aren't any left, then you won't get it.