Re: If you had to pick just one kind of wool...
I was going to say hand knitted is my favorite, but then saw that you don't care for that. If it's just because of the multicolored yarn, you can get them done in solids or a natural undyed color. The only mainstream wool I've tried (not hand knitted or upcycled) is Disana. I my Disana soaker for overnights, but it's definitely too bulky for under pants. I want to try Loveybums wraps, just haven't had the pp.
Like others said, if you're wanting it to go under clothing, I'd go with an interlock soaker, probably two layers to be safe.
: MM Dragon's Lair (2) + trim (1) on Uruguay 3-ply
includes Green Line, RagaBabe, BBB, Joey Bunz and more.