Sorry, I was hoping your budget might be somewhat higher. The two brands I mentioned are based in the US, so of course, shipping and VAT will increase the expense to you.
I'm not sure what brands to recommend that are readily available in the UK. Don't bother with Bose, of course: they spend their income on advertising, not product development. Pioneer might be appropriate: they're well known for quality speakers, although not so much for their in-home subwoofers. (They're heavily into car audio.) And, of course, you might want to investigate pre-owned equipment. That could stretch your budget quite a bit farther.