I need something that can stick to a 600whp car. A lot of fast guys use 285s for some reason.there aren't exact size of R888R for Supra. you may have to up the size or down the size a bit. however, what is your goal to achieve by replacing tires? track driving? street driving? all weather? drag? the term "Best" is relative and vague if you don't have goal.
for example, R888R might be the best trackday tire to drive to track and back but it's terrible as drag tire and makes a lot of whining noise. you may find other tire such as pirrelli P zero for street tires as best but would be terrible on all weather and drag.