I don't usually deal with studs that wide, and I'm not sure what limitation you're running into, but maybe use track sections with strapping? Cut track sections a few inches longer than the stud spacing, clip the flanges and bend it back so the fit snug between the studs, screw the bend portions into the face of the studs. Then run a continuous strap along the face of the wall (the tension side doesn't work so well on the bent track).