Just going off specs sheets from manufacturers and reviews (mostly consumer products, so enterprise should be the same or better).

There are only a few major NAND manufacturers: Samsung, Micron, Kioxia / Western Digital, SK Hynix, and their branded products are usually the best.

There are also several 3rd party controller developers: Phison, Marvell, Silicon Motion, which I think are the largest, and then a bunch of others.

I hadn't looked at this in a couple years, so 16 channel controllers are more common now, but only on high end enterprise devices.

4KB random read/write specs are definitely not trustable without testing. They are usually at max queue depth and, at least for consumer devices, based on writing to a buffer in SLC mode, so they will be a lot lower once the buffer is exhausted. Enterprise specs might be more realistic but there isnt as much public testing data available.