CSL specialist garage advice?

[GTAStradale]

Hi there, I live in Switzerland and my CSL has 98.000km on the clock. It is in a good condition, however, there are signs of work that needs to be done. I would need to do the following:

1) Put on new OEM suspension and all bushes around it (currently Billstein PS09 is on)
2) Put a new clutch
3) Check if anything else needs an update (last BMW service was 5.000km and 2 years ago)

My aim it to keep the car as original as possible. I own it now for 7 years and wanna keep it hopefully forever, but still want to make sure it is serviced in a specialist garage to keep a spotless history.

Can you help me recommend some CSL specialist garages in UK (not too north from London), Germany or Switzerland? Also how much would something like that cost - I am considering UK or Germany, since Swiss prices are very high and not much CSL knowledge here (91 cars sold in total).

Many thanks in advance!