Thanks to all for your replies. I wont be doing the cambelt myself and will be having the water pump replaced at the same time too.
There appears to be a wide variety of costs depending on who fits the Cambelt and some special tools are required including grinding a semi circle out of the engine mounting so that the timing can be locked with a pin.
On the plus side it only needs doing every 8 years and perhaps its a small price to pay for peace of mind.
