Kevin here will probably address this further, but he is not here today. He will reply Tuesday most likely.
For a mildly modified MK3 Supra Turbo I would recommend (quite highly) the RPS Sport/Street clutch. It is barely stiffer than stock (about 10%) and has a solid-face disc that is very easy to slip. But it is rated to hold a LOT more torque than the stock piece.