Its ok to put them inverted but his pint is valid too you can remove the Cups so that dust dont stay ...
beside I think you will be need more longer handle bars so that you can have a Good laid back seating as in cruisers/choppers or else ridder will get a muscle fatigue...
hey , Hid Idea ... Why dont you create a Chopper Handle Bar it wont Cost mush and you can put all you creativity... 