I would generally recommend either 24-bit/48 kHz or 32-bit/48 kHz (either float or integer formats). There is a user option in Hauptwerk to convert anything with a resolution above 16-bit either to 16-bit or 32-bit. Hence there is no memory saving by using 24-bit instead of 32-bit. If your samples are 36-bit, you may as well use 32-bit, although the difference will be almost undetectable, and more media may be required for its distribution.
Martin.