With 4k I would to go for a Focus or Fiesta, I think you're always risking trouble with a Vauxhall? The Focus of around 12-14 years ago, particularly, was seriously over engineered which is why you still see so many of them around.

I had one for 4 years, approaching 200k miles, it came to grief at the hands of a 95 year old lady driver. Her car was wrecked, the Focus stood up well but, alas, even the minor repairs required were deemed uneconomical.

No help to you, admittedly, but if it assists anyone else avoid a similar issue...

The Astra G and H 1.7 cdti variants were really good. Newer ones not so good from what I have heard.

Ford Focus around the same time period are indeed decent. Going to try to get one at some point.