Its always said that tall riders should rider 69ers or 29ers, but assuming that you already run a larger frame which would create a slower steering bike in the first place, why exaggerate the problem by adding larger wheels.
I believe that normal etiquette would have the man laying on his back whilst the woman straddles his face, thus avoiding choking. Though some of the films that I have seen of late seem stubbornly opposed to my description.