Thanks for the hints
I think I'll go for SP upgrade.
I've made a list of parts needed:
LA254 - Knuckle and Hub Carrier
LA255 - Lower Suspension Arms (2x)
LA257 - Front CVD 73mm
LA258 - Rear CVD 60.5mm
LA252 - Rear Hub Type C
LA253 - Rear Axle Spacers
LAW31 - Aluminium Front Susp. Holder
W5184 - Triple Cap Shocks
LA256 - King Pins
w0144 - Alloy Washer 3x7x2mm
w0145 - Alloy Washer 3x7x1mm
Anything missing...?