if you want a crazy performance longboard, i would suggest no to go with belt-driven
i own 12s 192kv one motor board, and i have some issues with belt-pulley system when i “floor” it. because im using almost full potential of motor, belt system struggles to handle that power. yes, it possible that you could find a way to improve belt driven system. but it would still louse power on friction/noise and so on
hub motors would rule them all. just wait for your raptor 2. you would never make your first build as good as raptor 2
nevertheless, if you still thinking about making it by your own, find motors with less kv. 192 is too much. with 14/40 gear ratio, 97mm wheels, 47km/h top speed, i have issues with pulleys. 14 not enough for belt to handle power.
for single motor i would suggest 125kv from hobbyking, but its too big for 2xmotors
once again. hub motors.