mmm... i dont think the SC is as fast as you would like. 1/4 times are only in the 14's 0-60 would be low 6's? at the time i think the sc and the gs were the fastest but i would think that the new IS330 is the fastest...
here's something you can do. if a 98 sc isnt as fast as you like you can always swap in a zo6 engine!