The sticky at the top of the room details what I believe to be the easiest upgrade to S2 brakes retaining the original wheels.

Front: Cossie 4x4 callipers with Cossie 2WD 283mm disks.

Rear: Cossie 2WD rear disks with RS2000/XR4x4 callipers.

Both very easy upgrades and you can keep the original rims without taking any grinding tools to the bodies of the callipers.

Take a look at the sticky!

Lee