If this was just for your own self in your home, then have you looked into making them? I've seen some where friend long ago made her own for warmth, gloves and not mittens. I'm sure that there are directions online somewhere, but if I remember correctly, they started out by drawing an outline of her own hand and going from there. Knit cotton for the backing for flexibility and woven (could use denim?) for the palm, for strength.
And maybe a strap that goes through your bra straps from arm to arm holding them up? Or use a length of tighter woven for the top few inches of them.