Alex at AKS Tuning is in Bedford...
http://www.akstuning.co.uk/I have done loads of PCV, Cam Follower and DV changes on my own cars but never on anyone elses. I would not do either as if anything goes wrong I am not insured or have proper premises to repair other peoples cars.
Not knocking anyone's mechanical skills on the forum in any way, Just be aware if anything goes wrong replacing any of the parts you want doing you do not have a leg to stand on!
Where as if Alex or the likes does the job...You get the idea!