Among many clever features, the Onkyo 905 gives you two HDMI outs (ideal if you're running both flatscreen and projector), plus oodles more power. And you won't really do it justice with a £1000 package - even if you're buying traditional speakers, which offer more bang per buck.
However, the 875 in tandem with something like the B&W 685 Theatre (review
here) or Tannoy Mercury F1 Custom 5.1 (
here) would be awesome.