The best way to set up an SJS/SJG for indirect grilling is to put a small rectangular drip pan in the middle of the grill, on the charcoal grate, and to make two side piles of charcoal, equivalent in size. If you're using an SJG, do it so that the coals are perpendicular to the side air vents, not against them: doing this will ensure that you get a proper convection going once you put the lid on.
My rationale for indirect cooking down the centre of the grill is that, basically, that gives you the most room with the dome of the lid directly above your meat. You could lump all the coals to one side and grill on the opposite side, but because the grills are so small, chances are that your food will be touching the lid.