there are loads of diffs about that will do the job, along with strength comes weight unless your paying for mag units, a mag 9" ill cost you approx 4.5k, and alloy 9" 3k and work down from that, the rest are cheaper, but theres alot more work to do to make them fit, labour hours/materials and shafts etc.
Lee is testing out a new diff in his car. if he wants to tell you what it is then im sure he will.