question bout wheel fitment

what is the diff. between low and hi disk when purchasing rims cuz im in the process of buying a 2000 gs300 and looking at some wheels 19x9.5 et15 front 19x10.5 et15 rear and dont know if they fit or should i get something more aggressive?? i want to get that fat@ss lip in the rear and in the front.

disc is the mounting pad depth. you use high disk  to clear for big brake kits.  low disc normally in the rear to maximize lip size

thanks...i kinda thought that just wasn't sure