...and look what you've gotten yourself into Bernd, my journeyman friend, I gotta respect the attitude of inquiry you've taken on this and I'm excited for you. I think you've gotten some great advice from Kexo and Woochifer. Inkeeping with the points of discussion regarding MC playback (from true MC recordings NOT 2 channel matrixed or NEO:'d) I would humbly add a few observations:
1) I'm backing the guys on the "ambient cues" issue because I've been there and heard it with my system. Sample Jarvi/Cinn Symph~Symphonie Fantastique Mov.5. I can hear, from the rear, violins. Not direct source mic pointed at a violin, I'm talking about a mic pointed at a wall picking up the reflections of notes played by a violin. Throw in a few muffled sniffles, baton taps, etc. and I'm in the 10th row.
2) This on my system which is decidedly mid-fi, I guarantee that on the caliber of system you're putting together you will hear these types of nuances.
3) I like the idea of using the ARTs or Sigs or at least something you are familiar with and like the sound (I mean its not that different). As an aside, MC generally downplays "holographic imaging" in the front a bit, in turn favoring a more "coherent and seamless soundstage" across the board. Knowing your taste to some small extent, I believe you may want to look for a speaker with very forward imaging so as to retain some of that quality through the processing.
4) I didn't start to enjoy MC fully until I had floorstanders in back. Sorry to the bookshelf/surround crowd but IMO that is how it plays out.
5) Like any other audio situation, source material is crucial. Yeah you can load up on classical (at least one or two for reference) but that's not really your bag. I'm thinking you've got to get Dave Alvin~Blackjack Davidand some Keb Mo on SACD. You'll be able to A/B vinyl v. SACD if you so desire.
6) You'll want a good sub
7) How about a tube SACD?

You are in the business if teaching a dog some tricks Bernd. It could be that MC will never unseat your analog 2 from first love status, but I would be willing to wager heavily that if implemented properly you will walk away with a newfound respect for the MC format. And, of course, the journey and the discovery is half the fun...


As always cheers to ya,
M