Sculpt looks ace. the upper body of 4 with the skirts of 3 would make a nice combination. feminine sihlouette with quite a bit of boobage. but still in the realms of a real dress. (and not fantasy underpants.)
Man this is some great work! I like 3 the best. Could use something like in your initial concepts to scruce the silhouette though, sinmple shoulder pads or those spikey things would look good.
Looking sweet. Design of 2 seems hottest, but maybe bit to reavealing. Maybe if you go with 3 or 4 and added some holes eg. at sides of pelvis area, it would create some more variation in desing (negative space as someone mentioned).