Just posting this here because I fell in love with this dress! It's in .zpac and obj format fitted to G8F. I followed the tutorial in the comments section to turn it into a DS dress and it works beautifully. Trust me, if I can do it anyone can. So easy! (Make sure to follow the tip about the sleeves further down the comments)
There's also another dress by the same creator, but I didn't try it yet.
https://www.deviantart.com/enchanted-april/art/EA-s-RegencyDress-01-906446038