Ok, just by way of an update and to close this thread off.......
After the Bilsteins I ordered fiiiiiiiiiiinally arrived (20 days, despite having been offered and paying extra for 5 day shipping),
I booked the car in to a specialist 4x4 shop over here called AAA. The owner came for a quick drive with me after 10 seconds said, " Hmmm, they've tightened up the control arms with no weight on the wheels."
So, they changed out the ruined bushes, pressed in the new ones and installed the 4600 struts with new top mounts and isolators.
The noise has gone!! I love my Jeep again.
So, word of advice, if you install new LCAs, make sure you lower the jack so that some of the weight is on the wheels before torquing up those bolts.