i'm 6'3'' in the same boat.
they make urban punx in 184 but they're soft as tits. volkl walls are good park skis for tall people because they're stiff, but they don't actually measure out to 185 cm. and k2s new kung fujas comes in 189, but they're in the 90s at the waist. so yea, theres not much you can do.
i wish one of the small ski companies (hint- moment or boone) would make a park ski in like 186-188 or something around there...you'd be suprised how many tall people there are on the slopes.
i think you should deal with the width and get the kung fujas in a 189cm but if you are picky about the specs then 4frnt MSP as its good as its gonna get for you in a 187cm