Khloe Kardashian and Lamar Odom
Sthanlee B. Mirador/Shooting Star
09/23/2009 AT 06:15 PM EDT
As Khloe Kardashian and Lamar Odom prepare for their last-minute wedding
, slated for Sunday in Los Angeles, invited guests are also busily buying gifts and ensembles for the star-studded ceremony.
PEOPLE confirms the guest list includes Ryan Seacrest
, Odom's L.A. Lakers teammate Kobe Bryant, reality TV star-jewelry designer Brittny Gastineau, TV personality Lala Vasquez, and publicists Simon Huck and Jonathan Cheban, who are developing a reality show about public relations with Khloe's older sister Kim
"I'm running out now to buy a gown!" Gastineau tells PEOPLE. "I have no idea what I'm going to get. I have to get something ASAP. I'll go to Beverly Hills somewhere."
And has Gastineau, who frequently appears on Keeping Up With The Kardashians
, checked out Khloe's gift registry
on Williams-Sonoma? "I haven't gotten a wedding gift yet either," she says. "I need to get that too! I'm going there now! But Khloe's definitely not a difficult person to get a gift for. She's cool."
Gastineau, who designs the jewelry collection Tres Glam, says of the wedding, "It's going to be glam. I'm so excited for the wedding. I'm so happy for Khloe. That's the way to do it: Just meet someone, and then know right away he's the one, and boom – do it. There's no need to wait forever! That's what I want."
And Gastineau, who's single, joked to PEOPLE, "Kim is supposed to be my date! But she's going to be so busy running around, I'm going with my friend Lala." And Gastineau is well aware of the running gag that weddings are the perfect place for single women to meet their own future husband, joking that she hopes to catch Khloe's bouquet. "That's where I'm going to meet my husband!"
Don't expect Khloe to change when she's married, Gastineau says. "I don't think people change because they get married. Khloe is very strong."