Justin Guarini with Reina Capodici and her daughter Lola
09/25/2009 AT 01:35 PM EDT
Justin Guarini is known for his mane of wild, curly locks – but these days the singer's smile is even bigger than his hair. And for good reason: He announced Thursday that he's getting married
over the weekend.
"He's doing really well, he's excited," says Guarini's pal and publicist Jeff Ballard. "This is the happiest I've ever seen him. He's smiling from ear to ear. I don't know what's bigger – his teeth or his hair."
On Saturday, Guarini, 30, will wed Reina Capodici, 27, of Doylestown, Penn., who went to high school with the runner-up on the first season of American Idol
As for the weekend nuptials, "It's going to be a small, intimate wedding just for the families," Ballard tells PEOPLE. "It's really just his family, her family and a few close friends. But they're going to have a celebration, probably after the first of the year, for all their friends."
The wedding will take place in Guarini's hometown of Doylestown, Penn, where he has a home not far from where his parents live.
Guarini and Capodici will recite vows they've written themselves – and Capodici's daughter Lola, 4, will speak at the ceremony.
"She's going to have some vows to recite as well," says Ballard. "She's the cutest little girl. Justin just adores her."