Well, I have jumped in with both feet...... a set of 4 Continentals (non - run flat) tyres have been ordered, and will be fitted on Saturday.... now to find a spare rim to put the better of the two fronts on.

I did phone my insurance company to check that it was OK, they said that as long as the tyres are the right size and speed rating, they aren't worried whether they are run flats or not.