If you'll forgive me, can I suggest a different direction.
I'd buy a home theatre 5.1 setup from Samsung, Sony, LG, etc. Make sure it can decode at least Dolby Digital and hopefully even DTS. Those logos are usually on the box.
If your Sky+ box has optical out, make sure the amp has optical in, etc. You don't want to buy converters or being forced to swap audio cables.
The Onkyo SR506 amp plus a set of Tannoy FX speakers shouldn't cost much more than £350. For that you get an HDMI switch with 3 inputs, 2 optical input and 2 coax 4 potential input digital audio devices) DD/DTS/DPL PLus decoding and a fairly solid set of surround speakers.
Can be had from Richer Sounds.