We’re not sure if Rock & Republic will ever be our favorite to wear, but we can say unequivocally that the folks who run the label and RADAR Entertainment, like, totally rule. On wednesday night, they threw a party to “celebrate summer” at the Beatrice Inn. James Murphy of LCD Soundsystem D.J.-ed, and booze flowed like Amazonian rapids. As expected, much dancing and drunkenness occurred. Everyone was having such a blast that when it came time to shut down at 11:30 p.m., Rock & Republic designer Michael Ball just threw down a wad of cash (or whatever high rollers like him do) and bought out the open bar till the end of the night. It’s up for debate when, exactly, the party turned into a full-on rager. But we’d place it around midnight, when Australian pop singer Sia started a clear-the-floor dance-off with her girlfriend, JD Samson of Le Tigre. Frankly, those two were just one ball of hotness the whole night. Our friend who got to the party before us said Sia spent most of the night sitting in JD’s lap, legs wrapped around her waist, “rubbing up all over her.” Kirsten Dunst, too, was a dancing fiend (at one point we saw her do that “broken arm” dance move from the eighties), though she mostly stayed in the D.J. booth, where her friend and Beatrice house D.J. Matt Creed was spinning. We’re happy to report that Dunst, who’s in town filming the detective thriller All Good Things with Ryan Gosling, looked really healthy and didn’t drink all night, as far as we could tell. Jada Yuan nymag.comAnd from www.blackbookmag.com another report of the evening.We arrive at the Beatrice much later than intended. But Rock & Republic’s “Summer at The Beatrice Inn” has been mercifully extended for the entire evening. Already enveloped in a martini haze, we dash to the all-too familiar bar, and are reunited with the Inn’s usual suspects. I recognize Sia, the dog-loving musician whose CD, Some People Have Real Problems, I’ve had on repeat on the office surround-sound these past few weeks. I say hello to the sprite songstress, and tell her I love her dog. She looks at me quizzically, and I relent to explain myself. I rejoin my friends as standard Beatrice whispers ensue, “Did you see Kirsten Dunst is here?” my friend B says excitedly. I look over to see the lovely ing