That is a hell of a lot for insurance, have you searched around a lot? Tried going fully comp with a reasonable voluntary excess etc?
The mk5 Golfs are good in general, feel solid etc (I've got a mk5 GT TDI myself).
Focuses are supposed to be very good to drive for the money too.
Be careful though, just because buying a newish car is cheap, they can be fairly pricey to fix if they go wrong. I bought my Golf with ~30k on the clock and that had a couple of things go wrong this year that cost £1500 to fix. You just can't tell how things are going to work out.
Also, after owning the diesel for a year I definitely want to get something petrol and fun to go alongside it. Sure the my engine is punchy as hell, but it's not a
very fun drive. Bear that in mind