The only way the Jazz sign a impact free agent is if they trade Kanter at the deadline. Otherwise, they don't have cap space, and if Kanter makes it to RFA they will extend him or match his offer.
A better question might be "Will the Jazz use their boatload of assets to make a blockbuster acquisition this offseason?"
That's really the only way they can make a big splash, or through a sign-and-trade. . . but they have to send salary back if that happens. My personal preference is for them to trade Kanter, Burke and assets to grab a player here at the deadline (hopefully young and cheap) and then use their newly created cap space to make a splash or buy a bench. Not sure I'm sold on Kanter long-term for big bucks. His knee still worries me.