yes would be a nice little system. Couple of pointers-  i did look into McIntosh headunits but found their lack of removable fascia to be quite simply ridiculous. I wouldn't spend over £1k on a headunit and be forced to leave it open to thieves. Unfortunately the same is true of many decent headunits- Clarion HXD1/HXD2/Rockford/Denon 8245/8255.

I've just opted for a Becker unit- whilst not quite the same SQ level as a McIntosh it does offer a fully comprehensive sat nav, as well as Bluetooth and mp3 for the price of the Mc, plus face off

Amps- the MCs will be fine. Other makes to check would be the upper model Audisons. Speakers....wouldn't recommend the Dyns personally. Try the upper Rainbow or Focal Beryllium Utopias. The latters go very nicely indeed with Audison amps.

The JL W6 sub is good but could you not stump to the W7? Alternatively i went for a OZ audio Matrix Elite- the same sq and power of a W7 but significantly less money  Catch us on msn if you need any more details.

You say its a quiet car and others have pointed to the likes of Dynamat...very worthwhile. I've actually taken the seats etc out and done under the carpet of my Focus with Wickes flashing tape- very cheap but not too bad. I've also wired the speakers with Nordost Flatline Gold speaker wire , which sounds great and i'm using Chord Chrysalis home hifi rca's. As far as i'm concerned if its good enough for highish end home hifi then its fine for ICE