Hi Sheridan in Chicago!
Why don't you fabricate your own basket? I learned to take my stone
(that had a deep belly) imbed it in clay or children's play doh,
with a little extra depth to allow for prongs. Then pull the stone
out gently, fill the cavity with investment and let it get hard. When
the investment is hard (an hour or so), you pull the investment out
of the clay and turn it over. You now have a cast of your stone to
create your basket. Cut your wires and solder! Piece of cake!
Vi Jones in the beautiful Pacific Northwest