I have a Silver Smoker which is a small off-set like yours. I use a loaf pan as a water pan at the fire box end. Mostly cuz its too hot to cook there and helps even out the temps across the chamber. Fill the pan with water at the start and add as needed during the cook. Works for me.
A lot of people use water pans with a CG & have great results. I don't use a water pan. Instead, on my CG, I put the cooking grates from the SFB inside the MC, flip the ash tray & set it on top of the grates. The ash tray works as a baffle to help cut down the hot spot & even out the temps across the MC.