Always do a 66w (6 motor) drive. 4 motors are usually never competitive.
Checking out Xeon’s great post:
I would go 200 rpm (green motors) geared up 72:48. May be a little slow for this season, but that’ll be the best for 200 rpm on 4 in wheels. Most drivetrains in VRC are around 62-72 in/sec, so you’ll be on the low end in terms of speed.