Here's the partydress (one of not so many originally in-game clothing pieces that I don't hate) converted from AF to AM and made top only. It has fit and "fat" morphs and it shows up in men's in everyday category. I used HQ textures found here as a default texture replacement.

The model presents Wedges bottoms that go with this dress very well.

It may be a bit wonky in the chest area as I had to manually adjust the mesh. Body shape based on TransShape WSOs