Good luck in your search.
If you don't find what your looking for...
To make your own isn't hard. Keep in mind, the weight sits on the keel
, and the supports just stop the boat
from falling over. You want enough athwartships strength in the supports to withstand jostling from wind
, and yard trailers. And space your supports far enough from the centre of the boat
, fore and aft, to prevent your bow from dipping, and athwartships to gain leverage, and prevent side to side movements. Usually just inside the waterline. 'Cause just outside the waterline doesn't work
I'm sure there are lots of examples, wherever your boat lies.