Upside down calipers is a bad plan since you won't be able to bleed them. Doctor Diff sells calipers with dual bleeders so they can be mounted in any location. That is a very simple and very clever solution.
they are that way now, i bled them off the car and they have worked fine upside down but i would like to do thinks right if im gonna upgrade to the larger rotors.
Ive been in contact with cass from dr diff and he told me about his new calipers with dual bleeders. pretty nice setup