Yo toda la vida tuve broncas para dormir. Pasé por un chingo de almohadas (desde pluma natural, fibras sintéticas, memory foam, gel, acanaladas, tubulares, etc.) y siempre amanecía con dolor de cuello y la sensación de no haber descansado.
Fui al ortopedista y me recomendó las almohadas sobakawa japonesas (están rellenas de cáscara de trigo sarraceno) como esta.
Parece pinche comercial pero de un día para otro la calidad del sueño mejoró bastante. Son duras pero totalmente moldeables (a mí nunca me han gustado las almohadas suaves y pachonas). Se adaptan a tu cuello mejor que el gel o el memory foam. No generan calor ni retienen frío. No todos se acostumbran a ellas, pero yo no cambio de almohada lo que me quede de vida.
My kid, fiancée and I all have EDS, and the absolute best bed-related purchase has been buckwheat pillows. I've bought these ones, which are sort of expensive, but hold up well—mine's four years old and still great. They're obviously a lot firmer than regular pillows, so it takes a little getting used to, but they're our number-one must-have bedding item. Because they're both firm and mouldable, you can sort of shape the pillow to support you exactly how you need to be supported, which for me has meant that my neck is supported and head is cradled, and they're both supported enough that my shoulder isn't getting crushed out of place. I recommend them to everyone.
Dunno about hypoallergenic. It doesn't smell like anything. I found this much cheaper from amazon - $33 for a twin size pillow, which I think was $109 on the website you linked to. You could go smaller, like the standard Japanese size, but I kind of want it to fill out my standard pillowcases.