Well...only crickets chirping here so far so I'll make some noise:
Why don't you "kill 2 birds with one stone" and get a holster made of Kydex?
While my CC ankle-holster is an Uncle Mike's ballistic nylon (no sweating problem with ankle-carry anyway, even here in high-humidity & hot Texas) my OC holster is made of form-fitted-to-gun Kydex (from Comp-Tac online but they're made here in Houston), which I chose not for any sweating/moisture issues but rather, I needed a OC holster to carry a bigger gun in -- namely, my Colt 1911 Government (Series 80) -- when I visit an OC state (like "my" NM). Unfortunately, TX only allows CC. :-(
Still, a Kydex holster IS a "sweat-guard" as well as a holster, so for that particular (moisture) issue you might want to take a look at some in CC or OC versions.