For header clearance the em2 25mm hollow bar will be fine and it is not costly and OEM so good quality. For control, if you mean you would like a smaller sway bar to make your car oversteer more, the 25mm hollow is a little smaller than our stock sway, but you can also get the 15.9 mm sway which would make our cars rotate a lot nicer imo:dance:. It all depends on how you like to drive.