He wore the suit in only one episode ("V" for Vashon: the Patriarch), but that hat was in several. I think it's called a plantation hat. I don't think Alex O'Loughlin could pull that look off.
Unfortunately, embedding on the video's been disabled, so here's the link instead. He was on Jimmy Fallon at some point in 2010 and sang "New York State of Mind" and was phenomenal.