Focus estate - which engine?

[nogginthenog]

I have finally decided that the Merc has to go ( 1998 C250 TD ) - great barge, but too many electrical things that can ( and do ) go wrong. So to keep the Noggin family on the road I have decided to buy a Focus Estate, up to 3 years old and as low a mileage as possible. I really wanted a diesel, preferably a 2.0, but I have noticed that if I am prepared to have a petrol, there are many more 2nd hand options, and usually lower mileage.

Again - I would like the 2.0 petrol, but are there any issues with any of the engines that I should avoid? I can get all the performance figures / MPG figures online, but I'm looking for real-life feedback ( does the 2.0 petrol really achieve 39.8 MPG? ) If I go for a diesel, are the 1.6 / 1.8 good ( the lower VED £ is certainly attractive! ) What sort of mileage will any of these motors start to be potentially problematic? ( 135k on the Merc doesn't worry me, but anything over 50k on a Ford makes me nervous - rightly or wrongly ? ) . Any specific issues I should be looking out for with this model in general ?

Thanks in advance for your feedback.