"America is going to be a great wife," Indelicato tells PEOPLE. "She is so cool and so loving and committed."
Costar Ana Ortiz also has praise for the happy couple. "They are ready to start a new chapter together," she says. "That takes a lot of love and a lot of guts."
Ortiz quips about the Ugly Betty star, "Oh, and she will be bossy!"
For four years playing Ferrera's nephew Justin Suarez on the ABC comedy series that ended in April, Indelicato witnessed the couple's relationship firsthand and thinks she has met the perfect guy.
"I have seen the love Ryan and her have for each other and know it's going to be the fairytale life," he says. "Ryan is one of the kindest people I've ever met in my life. He treats her right and will always treat her right and love her. America is so lucky to have found him."
Ortiz agrees, saying Williams "is as motivated, hard working, kind and generous as [Ferrera] is, and that's not easy to come by in this business or on this planet for that matter. They are truly made for one another."
As for Williams, Indelicato says he will have a lot to gain by marrying Emmy winner Ferrera. Not only is she "going to make an amazing wife" but he's also gaining "an amazing friend," he says.