you definitely need hard wheels for skating a pool or a half pipe. 92 A is too soft! Get at least 95 A or 97 A. And get them with as big a diameter as you can. This (together with decent bearings) will give you the speed you crave.
I once tried 93 A wheels when I tried to make a skate which would be suitable for ramp and street skating. In the end, it wasn't suitable for neither. You need soft wheels (about 78 A) for the street and hard wheels (at least 95 A) for the ramp. Don't compromise. Specialise.