The Leon is a great all round choice. Cheaper to run than the Impreza and nearly as much fun.
I would advocate searching around for a good UK model relatively unmolested Impreza to test drive - you might instantly fall in love! (I'm on my 7th Subaru...
)As long it's a UK car (not Jap import), hasn't been mucked about with too much (an exhaust and brake upgrade would be nice), and has a fully stamped dealer service history then it should give you utterly bombproof reliability. Quite a bit of choice at 5 grand too. I would also suggest looking for a really nice MkI (around Y reg) rather than the MkII, and if it's anywhere near 60k miles make sure the 60k service has been done.