Good point there thom, now that you mention it there is a slight rattling noise coming from around the power steering pump, it almost sounds like something is loose internally! Are there bearings internally that could become knackered? Steering wise theres about an inch each way play in the steering wheel before the steering turns the wheels. Is it possible the power steering unit is about to pack it in?
Also yes, I checked the wishbone bushes and ARB bushes, no signs of cracking or excessive wear, which lead me to think it would be the shock top mounts.