This picture is a Corian sink seam undermounted into an engineered stone top, taken at a trade show. No gunk, no caulk line, no maintainence, looks fantastic, and there is not a more sanitary installation to be had.

Silestone manufactures engineered stone bowls that can be seam undermounted. And they have a line of washbasins as well. You may want to consider the washbasin route when you get the price for integrating an estone bowl into an estone top. It's unusual. Unusual means higher risk for fabricators and subsequently a higher price for you.

Karran shows their sinks seam undermounted in estone here. Karran makes nice sinks.

If your estone top will be the same color as your bowl, insist upon holding the slab and bowl adjacent before fabrication please. Since they aren't cast in the same batches, there could be a significant color difference.

In my previous house I used white Corian with an integrated sink for a secondary bathroom. Works well, looks good and easy to clean.

The first house we owned had a kitchen with Corian counters and integrated sink. No worries with cleaning a counter lip or bead of silicone!

If you are doing white, then just use Corian.

I agree if integrated and white is your choice then go Corian no brainer.