Having had a quick google about I can't find anything seriously wrong with that Pinnacle unit Mike. Assuming you have a router with wireless capability then I think it ticks all the right boxes for streaming internet radio (without the PC being on) and should also work for your MP3 collection - although that is probably better served by just plugging in a USB drive. It would take £60 away from your budget for the hi-fi but that shouldn't be a problem.
Mr Chris : its a corporate attitude with Sony. They DO treat the European market as morons on everything. I've lost count of the number of times I've seen Sony litigating to "protect" their market - they do it with anything that is in the "grey channel" and every UK retailer has been on the receiving end. For example ask Tesco what happened when they couldn't get PS2 boxes through the normal channels due to "shortages" but could get as many units as they wanted through the grey channel for 20% less! I wouldn't buy a Sony product if it was the only thing on the planet which did what I want. Really.
Edit - grey channel = not Sony approved distributors for the area, although they are approved for other areas. In short it's a fix to keep prices artificially high.