You can use separated bottoms and tops instead. If you use only male tops that are untucked, you can simply get all female bottoms and enable them for males in Bodyshop. The untucked shirt hides the difference between the male top and female bottom, so you have males dressed as females (with high heel inclusive) without boobs.
do you know how to convert the gender of a cloth in bodyshop? how do I do this?
If you are trying to do what was mentioned above and only make some of the female bottom separates available for men, then you don't have to worry about the neckline. And using untucked men's tops may cover up the mis-matched meshes at the waist. But you still cannot do this in BodyShop. To make a bottom separate available to both genders, you would edit the package file for that separate in SimPE, find the Property Set and change the Gender entry to 0x03. (0x01=female, 0x02=male, 0x03=both).
I've never done this exact thing so I don't know how good it will look. The untucked shirt may still show a crease or gap in it at the waist.