As I said in the other post re systems; I stream via AirPlay to my ATV2 and that to the amp via an MF M1DAC and the system sounds superb!
It may only stream at 16/48 but it's upscaled to 192 and sounds fantastic. As good, and at times, a bit better than my Rega Apollo which I've done a bit of side by side demoing today (it's been great fun)
The poorer recorded CD's like Jethro Tull, Frank Sinatra, Dean Martin, some Pink Floyd and some Iron Maiden as well all sounds a lot better via the DAC than it does on CD via the Apollo
Yeah all my iTunes music is in Lossless and not MP3 but still; it sounds superb 8)
ATV's can be had fairly cheapo now; more so 2nd hand via eBay and the likes...
Plus if you had the likes of an iPod or 1st Gen iPAD you can have iTunes on there via the Remote APP and, as I'm doing now listening to Pete Tong on Radio 1, use the TuneIn Radio app and listen to loads of radio stations plus those already on iTunes!
Personally I'd go for an ATV/ATV2 with a basic DAC (i.e. Lindy DAC for £40); connect those with a toslink cable and then connect the DAC via RCA phono cables to some decent active speakers like the Audioengine A5's. No amp or CD player needed. Just use your MAC, iTunes and AirPlay