Photo: ABC/MATT KLITSCHER

"The Bachelorette" Ashley Hebert will receive a bended-knee marriage proposal tonight from one of her final two suitors wearing a sparkling Randi Rahm gown and a new accessory; a blinding diamond-and-platinum Neil Lane engagement ring, StyleList has learned.

The ABC reality show's resident stylist, Cary Fetman, tells StyleList exclusively that he and Hebert chose a blush-colored Rahm gown with crystal and feather accents.

The soft chiffon gown features custom details including handsewn ostrich feathers fastened with crystals; a dramatic contrast to the sandy, windswept bluff where the show's final rose ceremony was staged. "I knew the bluff was breezy and I wanted her to wear something soft and romantic that would blow in the wind. I really wanted to amp up the sense of romance and just have her looking gorgeous, which she did," Fetman says.

Fetman chose strappy Roberto Cavalli sandals and pearl drop earrings by Cezua of Beverly Hills to complete the look. The earrings have an unusual feature; a white pearl dangle for one ear, a black pearl for the other. "I loved the way they were luxurious and earthy at the same time," Fetman says.

Philadelphia-based dentist-in-training Hebert is expected to entertain possible proposals from J.P. Rosenbaum, a 34-year-old construction manager from New York City, or winemaker Ben Flajnik, 28, of Sonoma, Calif.

Fetman told StyleList he turned to Rahm, whom he has worked with to dress Sarah Jessica Parker and Julia Louis-Dreyfus for red carpets, because her collection epitomized the sense of allure and romance he wanted to evoke for his reality muse. Hebert wore a sexy, gold gown by Rahm -- known for her intricate bead work and luxurious details -- to greet her 25 suitors on the season's premiere episode in May.

Although Hebert had a complicated path to find primetime romance, Fetman says it was love at first sight with her finale dress. "Ashley saw it and said, "Cary, I want to get married in a dress like that,'" Fetman recalls. "I told her "Ash, I don't know about the married part, but I'd love to see you get engaged in that dress.'"

Meanwhile, sources tell StyleList that Hebert will receive an "absolutely beautiful" Neil Lane diamond of several carats set in platinum from one of the men. The celebrity Beverly Hills jeweler has supplied the bling for proposals on "The Bachelor" and "The Bachelorette" for several seasons now.

While Fetman could not dish on the man Hebert chooses as the recipient of the show's coveted "final rose" quite yet, he seemed ecstatic about the outcome. "Dressing them for this special, romantic moment in their lives was almost as much fun as watching them fall in love."

Meanwhile, read our exclusive interview with Lane about his role as the reality franchise's go-to jeweler.