There's no such thing as a minimalist downhill, telemark, or AT ski boot. However, there IS a way to fit boots that will make your feet much happier, and it has nothing to do with how most bootfitters work.
Most bootfitters will do a "shell fit", where they evaluate the fit by how many fingers they can shove behind your heel. They'll try to put you in the narrowest "last" (measured at the ball of the foot) they can, and with the least amount of room for your toes that they can.
This is baloney. Crushing your toes does nothing for control of the ski. Zero. Zip. Nada.
What gives you control of the ski is a tight interface between the boot shell and your shin and instep. Your heel shouldn't be able to come up off the boot board by much, if at all, and your shin should contact the entire tongue of the boot, not just at the top. Otherwise you need a lower-volume boot, where that contour matches the contour of your own shin and instep. (A low instep is a "low-volume" foot, and a high instep is a "high-volume" foot.) Alternatively, if the boot crushes your instep, you need a higher-volume foot.
Concentrate on the place where your foot and shin meet. If there is space there, your foot will slide around no matter what you do! Find the widest boot you can that holds that area down securely. If the shin/instep interface is good and your ankle/heel is held securely, you ought to be able to saw the toe of the boot off entirely with no loss of ski control.
Contact me through my website if this isn't clear. I know my skiing biomechanics, I know my ski boots, and I know what you're after here. And there's more to it: this is just the start.