Change sex without changing appearance

[theozcall]

I'm sure this is a no given the amount of requests for mm/FF aaf plugins, but worth asking if there's a way to change an NPC's gender without changing  appearance or voice?

So they would register in aaf as the opposite sex and allow the animations to work accordingly? 

Thanks!

[theozcall]

Alternatively, anywhere to source m/f nudesuits that can be crafted/console commanded and NPC's can be forced to equip?