Bespoke sinks are VERY pricy. Not many people want a 10K sink.

Prepare to be a$$$$$$$$$$$$$$$$$$$$tounded. But try Waterworks Made to order

https://www.waterworks.com/made_to_order/washtands_and_sinks

Or.........re think your trough to concrete and not ceramic

Gotta Google my friend.

Solid Surface like Corian will be much more reasonable.

https://www.wayfair.com/keyword.php?keyword=bathroom+double+trough+sink

We had a similar situation where we needed a custom top, we used white quartz and mitered the edge to give it a 3" profile on all sides with an undermount sink. Not exactly the same as porcelain but close enough

Ours? I have the master bath pretty much finalized minus the lights. It was the guest bath I had sink issues with. That's what happens when you find a vanity you love on Craigslist and need to find the sink you envision with it. This is the layout. You can't really get the visual though. We are doing 1 vanity that is 44 long, 19.2 deep, and putting the hutch that was in the kitchen into the corner of the bath for storage (after we strip the paint, remove the fake pieces of wood on the windows and stain the wood). Here are photos of the layout, vanity, hutch and tub. Just need to figure out the sink, purchase faucets, mirror and lights and I am done material shopping.

You might try a local potter. They might be interested in a unique project, like yours. The trough sink would add an element of style! Richard ships anywhere....custom sink (note: I own one of his sinks)