Workshop In Essex

Hi all
Not posted for a while, I'm on my third Triumph an 04 Sprint RS I'm looking for a reputable mechanic in the Essex area to do a valve check, I do my own basic servicing but I think it might be a bit ambitious for me to do it I've phoned around a few workshops and I'm not impressed, one guy quoted £500 and said its easier to take the engine out lol, Jack Lilley was the best said they would do as part of a major service £900. Any suggestions would be appreciated.
Matt.