The only slightly awkward bit is the valve clearances, which just needs a bit of careful measurement and the facility to store the car for a few days whilst you go and order the shims you need to set them correctly.
Thanks guys, If I get one I will be planning on keeping it for a long time so by the time I move on it will be at that age where condition is more important than full service history.
Is there any manuals or online material for repairs/servicing for either the Z4 or M3?