When designer Zac Posen launched his diffusion line, Z Spoke, in 2010, it was sold exclusively at Saks Fifth Avenue. Now that the lower-priced line has a store to call its own, fashionistas no longer have to trek uptown to get their hands on shimmering peplum blazers ($395), cowl-neck blouses ($195) and high-waisted stretch pants ($255). Once you step inside the ultramodern, red-hued interior, you’ll be greeted by a soundtrack the Misshapes created exclusively for the store blaring from the speakers. Browse through accessories such as embossed ostrich chain-strap purses ($495) and leather double-strap belts ($150). Don’t leave without rifling through the collection of rare and vintage fashion books, curated by local periodical collector and archivist Michael Gallagher, that are housed on freestanding bookshelves occupying the back wall of the store.