Why limit yourself to bezels with a built-in step?
If the bezel is closed back, simply make a loose coil of wire that
will fit into the bezel and place the stone on top of the coil. It
is well supported and you can burnish away. Use a different gauge
wire to raise or lower the stone in the bezel.
If your bezel is open backed, it will be necessary to solder the
wire to the bottom edge of the bezel and form the step.
Judy in Kansas where it hit lower 80s today... darn funny weather.