Youre having a hard time because hardly anyone makes leather-lined boots these days. Most makers use a knit nylon, as it requires no break-in and is pretty durable (also probably simplifies manufacture). But I agree that leather linings are great. They mold to your foot to create a custom fit, and, once broken in, they are extremely comfortable.
If you can find them, Raichles Mountain Crest ($185) boots have a leather liner. Ive worn similar Raichle boots, and theyre fantastic. Be sure to NOT get the GTX model with the Gore-Tex liner, as, breathability aside, those will be sweatier than the non-Gore-Tex model. Raichle boots are not as commonly found as they were once upon a time, but Oregon Mountain Community in Portland has them.
Another boot with a leather lining is the Limmer Lightweight ($265), made by a famous New Hampshire company. These boots will be a lifetime investment, I assure you. They are also available as a full custom boot, but for hundreds more and a long wait. Unless you have a weird foot size, you should be fine.
You may also want to see a podiatrist. You may have hyperhydrosis (fancy Latin term for sweaty feet"), and there are treatments for that.
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