Buying Advice Please

[athingofbeauty]

Thanks for the advice folks. I had thought that the HDI was much more expensive to run in terms of repairs than an XUD but i'm new to this scene. I have a young family so safety is important so perhaps i should go for an HDI. I don't want the hassle of veggie oil at this stage. Whats involved in a stage 1 re-map then, and what are the costs? Does this not put the engine under too much strain and will it become less reliable? The £130 tax is appealing. Think I might be swaying towards an HDI.
What goes wrong with these cars as the rear beams seem to be a problem - Do they snap?