Please avoid wearing black. Some of the online shops below sell outfits made to measure so you can submit your measurements and it will be custom sized. Otherwise you can order a standard size and get alterations if needed. Other than these tips, this is an occasion to bring out your bling, glam it up, and have fun with your outfit! We found a thoroughly documented wedding on a photographer's blog that will give you a good idea of cultural styles worn to this type of wedding: http://fenglongphoto.com/zahra-nazim-atlanta-ismaili-indian-wedding-at-baps-mandir-al-noor-and-sonesta-gwinnett-place/ Most importantly though, wear something you're comfortable in and that you like!
There are a lot of styles you can chose from. Lehengas, sarees, and salwar kameez are the most common women's outfits to wear to a wedding. Sarees require draping and would be the most complicated style to wear.
A kurta, jodhpuri, or sherwani are the most common men's outfits to wear.
Some options for online shopping are: https://www.manyavar.com/ https://phera.co/ https://theshaadishop.com/ There are also retail shops listed below.
GREENVILLE Benaras Boutique (Online and Retail Location) *By Appointment Only, Please Call* https://www.benarasboutique.com/ Greenville, SC 864-283-5602 ATLANTA Global Mall - Indian mall with many Indian clothing stores 5675 Jimmy Carter Blvd, Norcross, GA 30071