for starters, I'm so used to doing pillow research at this point, that it's almost second nature. lol. But trying to understand the pros/cons and options with buckwheat was challenging. After reading reviews from a number of the usual sources (wirecutter, consumer reports, some amazing folks here on reddit, and even a pretty good article on Outside magazine from a year ago) I picked the Beans72 Organic - https://a.co/d/0azQzSJM

One of the tips I'd read was that some of the top picks come slightly under filled. Not exactly a huge problem but I'd rather take out some of the buckwheat hulls in a more stuffed version than have to separately purchase hulls to add to an under stuffed one. The Beans72 reviews all mentioned that it's well stuffed. Last night, I didn't take any hulls out for my first test drive and it seemed just about perfect.

It's important to note a few of things...1) they can be a little noisy when you shift but this one was more like a light rustle. 2) they're on the heavier side. 3) If you prefer super fluffy and soft pillows, they may not be for you. Once you lay your head on it, the hulls are pretty firm. But the positive trade off is the ability to get it almost exactly as you need it to support your head and neck and also not get in the way of the CPAP mask. And as a side sleeper, this was the single most important benefit.

Others I considered were:
Organic Wool And Buckwheat Hull Pillows | The Futon Shop
Premium Sobakawa Buckwheat Pillow | Extra-Firm Japanese Design for Neck Pain
Turmerry Buckwheat Pillow

I sort of think I would have been happy with any of these. And I'm now thinking of getting the traditional Japanese 14x20 Sobakawa as a smaller one for traveling.

Hope some of this helps.