That's fair enough - I run an Airport-Express based system at home when i'm having parties, so I don't have to bother changing discs. Sounds fine through a good hi-fi system, as long as you keep things Apple Lossless.
Talking of which, I'd budget some of your cash for a good removable hard drive, to make sure you're keeping those music files uncompressed, or consider a network media player, which would cover the streaming as well as the storage. We've tested four of the latter in our next issue (out July 26).
After that, i'd plump for the Roksan Kandy L.III amplifier (£650), or the Cyrus 6vs2 (£600) if you want a more compact amp (that's also upgradeable in the future).
Then add the Monitor Audio Bronze BR5 floorstander speakers (£400), with some decent speaker cable (QED Silver Annivesary XT at £5.50/m). If you want smaller, standmount speakers, try the Epos M12.2 (£450, plus a decent pair of stands - Custom Design's RS300 at £85 or the Soundstyle Z2 at £60), or the Monitor Audio Silver RS1 (£350) plus the same stands.
Of course, these are just suggestions, and i'd strongly advise trying before you buy, ideally taking along your laptop to a dealer and hearing the system just as you would do at home.