It's going to always be hand-to-hand combat for Ivy. She is trained in less than lethal methods and (in a homage to 90's cartoons) prefers not to use firearms.
Jason always carries his Glock 20 chambered in 10mm. On the rare days when he feels like carrying something different, he reaches for his Kimber Crimson Carry II chambered in .45ACP. Jason likes the Kimber because its an old but tested design with a few modern features.
Actually, the only thing that wasn't stolen at the Louvre's Apollo Gallery is the Regent Diamond, figure no one would take it because something to do with a curse.