not benefit from being rotated. If the sculpture is
something with a plain surface to it, say it's a two-sided
piece, rotation may be more enjoyable on a manual bases.
Whether you decide on manual or motorized rotation
purchase pedestals made for fine art. Various attempts
at creating these things at home have gone awry with
monstrous results.
The speed of turn you'll find to best suit your
sculpture will be between one to two rotations per minute.
Any faster and you will find it zipping by too quickly.
What makes such an item a bit pricey at times is the
motor.  Professional grade pedestal motors can start at
$1,000.
The price makes a difference you may not
immediately notice in the gallery. There tends to be a hum
associated with these motorized pedestals and when you're
walking around talking with people, and the music's playing,
you won't hear it.
But sitting in your house quietly reading a book you
will find this hum tremendously annoying and then
you will know why a quiet motor is an expensive motor. At
the very least, make sure it has an off button.