That invoice is all over the place!
Ceramic pads?
Separate inner and outer bearings? They come in a kit which includes the seals @ £87.00 per side.
Genuine pads £22.50
Genuine discs £42.80 each
No charge for grease & sundries?
Lower king pin kit 162.00 each.
Wheel alignment @ $75.00 is cheap.
Balance 4 wheels @ $50 is about right.
Replace centre link should be 0.5 hours maybe 1.0 if there's any difficulty with seized taper joints.
Tie rods, during centre link replacement maybe 1.0 hour.
"Replace upper outer pins & bushings" 1.6 hours is probably not enough but why does that repair kit not feature on the parts element of the invoice?
Replace king pins. This is easily a four hour job per side, if not more but again no king pin set on invoice?
Replace front shocks. AT 0.8 hours is about right, maybe 1 hour. I take it you provided the shocks?
Replace steering damper should be max 0.3 hours.
Re-line front disc brakes & lube caliper slides. This is the strangest of all. Have they fitted new discs or not? They've invoiced you for them (rotors) and new ones certainly don't need "relining", whatever that is. As for lubricating caliper slides, that is just pure BS.
Replace front discs should be 2.4 hours and that includes adjusting the front wheel bearings. Replacing the wheel bearings at the same time would be an extra 0.5.
Bleed brakes & replace rear shocks is about right.
In short, it looks to me like the bill is probably considerably less than it should be but the competency (or in the worst case the integrity) of the garage is doubtful.