I have some leather gauntlets from the brand Castle. Very nice quality that has lasted for several years. They are thinsulate lined, but I feel like I have had warmer. Nice big gauntlets that cover the sleeve opening are utmost importance. I think I paid around $70-$80 and they may have been on sale at local mc dealership.
I had some swap meet cheapo-s that were warmer, but everytime you took them off, the liner would try to come out of the fingers, and if it did?, that's a twenty minute job trying to stuff it back in there. So beware of that super annoying problem.
Lots of guys swear by wearing surgical gloves under the warm ones, but I can't stand that slimy feeling. Plus, try getting a box of surgical gloves these days!