Thanks guys, the pads are doing well, with no noise whatsoever, so I'll leave the shims out. I retained the two rear shims which are in contact with the piston.

I saw a 'paste' at supercheap which you apply to the back of the pads to reduce noise as well, I may get some of that if needed as it looks similar to the Molykote M77 which is mentioned in the workshop manual.