Desktop Wanted ASAP - Requirements/Budget Inside!

Ok requirements as follows:

- Watching lots of HD/DIVX TV Shows and Movies
- Music (Will be connected to hi-fi setup)
- General use including MS Office / Messaging Apps
- Something quiet, really loud units are an annoyance
- Pentium
- Something which is futureproof and won't require upgrading for another 3-4 years at least
- Something good to look at would be an added bonus - my current home cinema set-up is black, so something to integrate with this if possible.

I tend to do quite a lot of things at once but nothing too intensive. The ONLY game I would ever play would be something like Football Manager so no real gaming requirement. Not sure r.e. the sound as initially I would use a Jack to Phono cable, but will eventually be upgrading to a DAC.

Ok budget is around £600 and would need to include a tower/lcd and peripherals if possible (although I could purchase these separately if need be). If I could something for my requirements at a price less than this, say £450-500ish, that would be great!

Want to purchase a pre-built system as I have no idea/interest in building something, and need something fairly quickly.

Thanks guys