Do you use sinks at the same time or are you only choosing them for resale? I really hate my 60" double sink vanity. We'll be changing it to a single sink for more counter space and drawer storage. Would you consider the 49" Impressions counter? I can't tell from Kohler's spec sheet what size the sink base needs to be in the vanity, but you'd want to be sure the two drawer stacks were at least 12". That's what you'll get in the 60" vanity. Or do an all-drawer vanity.

I did a very short cove that stuck up 1/2" and was the thickness of tile so I could do tile backsplashes with no caulk joint right in the corner

FWIW I got a Swanstone counter with integrated sink in white. Its solid white (and I love it - so easy to clean). Bought it at big orange for cheap, after reading so poor reviews for cultured marble (which wasn't that much cheaper).

One more option that is not at your list is quartzite. It is harder than granite, got the beauty of natural stone and once you seal it properly it will last a lifetime. Of course it is not easy to find a high standard of craftsmanship on this material because of its hardness and because it is natural stone. If it is done properly fully mitered and right crafted, it is incomparable. You can check the ones I did here: https://integratedstone.com/my-product/cristallo-quartzite-vanity-top-with-mitred-edge-profile-and-integrated-mitred-sink/ integrated quartzite mitered vanity