As far as importing goes, this is the information I have:
If you don't want to break the law, you could just wait it out. Atkinson is gone and the tide of opinion appears to be turning in favour of a R18+ classification. I predict we'll get one within the next year or two (I know that's probably little comfort to you). Unfortunately, even if that happens current RC games may not get reclassified.
And yeah, sometimes just... fuck this country.