That budget is for Amp, CD Player, and Speakers?
I think that is going to be a little lean, but we will see what we can do.
Stereo amps with digital input are rare, though there are a few around, but I don't think they will fit into your budget. The alternative is to buy an external DAC. These typically run in the +£100 to +£200 range.
But here is a thought, most good modern LCD/LED/Plasma TV's have multiple Digital Inputs. If your TV also has a analog (meaning not digital) output, you can plug all your digital sources into your TV, the connect the Audio Out of the TV to the stereo. The TV will also have a pretty good DAC (digital to analog converter). That is probably your cheapest option.
Next, how large of speakers did you have in mind? Basic bookshelf or are floorstanding speakers in the mix?
Right now, two of the best bargain are the 46watt per channel Cambridge Audio 340A-SE for
only £130 from RicherSounds.com .
In speakers, it is extremely hard to beat the Wharfedale Diamond 9.1 from SuperFi.co.uk for only £100/pair.
The next best amp is probably the 40w NAD C315 from (I think) SuperFi.co.uk for about £160.
You do have a little more budget, and Richer Sounds also has a few Cambridge 640A-V2 for only £199. This is a 75w/ch amp for about £200.
If you can handle a floorstanding speaker, consider the Infinity BETA 40 from HiwayHiFi.com -
INFINITY BETA 40 (BETA 40) 3-Way Dual 6-1/2" Floorstanding Loudspeaker Featuring Patented... - www.hiwayhifi.com
The Infinity speakers would bring the total budget (amp & speakers) to about £350. With the Diamonds above, the budget for amp and speakers would be about £250.
The Cambridge 640C CD player is about £150, and the lesser Cambridge 540C CD Player is between £120 and £150 from Richer Sounds.
For a radio Tuner with FM/DAB, the Cambridge model 640T is about £180. Though if you just want basic radio and aren't concerned about matching components, an AM/FM Tangent tuner can be had for as low as £20.
I suggest you browse around on the RicherSounds.com , Superfi.co.uk, and HiwayHiFi.com website and see if anything catches your eye. Report back, and we can discuss it.
When looking at speakers, especially bookshelf, it is important the the low frequency response is below 60hz. Ideally below 50hz, but that is somewhat difficult in a bookshelf speaker. In floorstanding speakers, the low frequency response should be below 50hz, and ideal at or below 40hz.
I probably haven't answered all your question, but hopefully I've given you enough to get you started looking at the possibilities.
Could you describe your Media Center a little more? Is it just a general computer used for media purposes, or is it a specifically designed Media Center, and if so, what brand and model?
There are many other possibilities and many other sources, but again, this is just to get you started.
Steve/bluewizard