ditching the arb for compression struts won't help as they will still be bits of metal poking at the same places wehre the arb was originaly, if anyhting because they are straighter they might even limit lock even more

what you would need to do is to move the whole wheel/hub/suspension assembly further out to give you the space to put the extra turn in for the wheel, and this ain't gonna be cheap or make the car handle any better as it'll tramline something chronic

other than putting custom suspension in place i can't see anyting other than spending loads of money to get what you want out of a sierra