I hope your dress works for you!
My personal unicorn (hewi) is a moto/biker style leather jacket that is somewhat fitted, and doesn't constrict my arms/shoulders or squish my chest. I've quit looking, because my lifestyle has changed to something that really has no use for jackets. I did find a scuba-type material model that fills the whole adequately enough and has stretch to accommodate the parts of me that usually feel constricted in jackets.
My other 2 unicorns were a knee high equestrian style boot, and a combat style boot. I FINALLY found them when I quit searching fashiony brands and checked into work wear brands. Now, I don't have to baby them, because they take the abuse I dish out, and they are staples for the brands I bought.
Beyond that, my lifestyle doesn't allow for wardrobe investments. I destroy clothes at an alarming rate, so I've quit spending major money on any one piece (except footwear, handbag, and a warm winter coat); irrespective of cost, I just ruin clothes. When I buy them thrifted/consignment/deep discount, I'm not too upset when another one bites the dust. I'm actually a bit envious of your white dress, because white in my world... yeah, it never stays white. Good luck with it, I truly hope you found your hewi!