Mcintosh MA6900 v Krell 400xi for S F Cremona

What do you folks recommend for driving the floor standing Sonus Faber Cremona speakers ?

I am a reletive audio-novice building a system from the ground up. I have opted for the Sonus Faber Cremonas and now have to choose a system to build around them.
Here are some of the requirements :-
1. 2 Channel , only for audio use. Home Theatre is in different room.
2.My taste in music includes:- female jazzy vocalists (eg Holly Cole,especTemptation,KD Laing etc),Rock (eg Pink Floyd,Dire Straits, Sting) and Blues.
3.System should not be super fussy about location. The room cannot be customised for the music....the architecture(contemporary,double height rooms) and the views are important. The current room is large 42'x24'+super high ceilings and balcony), so system has to be able to fill space, but also have the flexibility to work in a more reasonble space if we move.
4. Practical and Robust. Nothing esoteric. Something that can be installed easily, and will work without problems for years.
5. Exquisite for one and good in a crowd. This will be used for for listening to by myself in the evening(cocktail in hand enjoying the sunset), but also provide music for 100 at a party.
6. Clarity, great air, accurate but smooth ,musical are adjectives I read on this site that resonate with me.

My local dealer is going to demo the Krell 400xi and the Mcintosh MA6900 for me next week. What should I listen for ? What other choices would you recommend ?
I would like to keep the whole system cost(Speakers ,source,Amps,cables etc) under $15,000.

I am off to go skiing and watch the superbowl, so will return to answers on Monday. Thanks....and Go Pats.