Tamiyadriver the big deal on cutting and vents relates more to the rear of the body or changing wing size to change handling. A couple years back there were a few cars with taillights cutout to relieve pressure in the rear of the body aiding down force, along with wings cut down on the main plane to lessen drag.
Modena is still king but the new Calsonic is a good second if you are looking for a touch less steering. On either body get the lightweight version not many race weekends but very little weight on the car.
Kilruf I would avoid the Altezza unless the track is REAL loose. The body is top heavy but does make real downforce, almost too stuck