Mine, and most people I know using them for that matter still runs kit springs. It will depend on the track though - I'd start with the kit one and decided when you try the car.
To fit B4 wheels you will need:
Front axle
Rear washers
So far for me breakages have been rear towers (even carbon ones) and a front upright.
You will want the carbon steering link thought - that makes a big difference as the stock one is very flexy.