Suspension isn't really required for skid steering drive systems. It is a must for holonomic or mecanum drive systems if you want a good drive system. It shouldn't be too heavy though if you just have one half of the chassis rotate or if you have the wheel mounted so that it has some travel up and down like
488's mecanum drive system.
If you're thinking about suspension because you're worried of your electronics getting damaged if you go off a ramp or drop, then you could just mount the electronic boards on something to absorb the shock like rubber standoffs.