For $5K you can do quite well. I own a pair of Bachs
and have had them for a couple of years. My system has
really evolved over this time and so I think I have
a pretty decent idea of there vices and virtues.
The Vienna's bass can be a bit boomy if not setup correctly.
A good amp will go a long toward's fixing this. You have
a whole lot of choices. BAT,Krell,Pass Labs, McCormack
etc. Krell might be a good match with the Mozarts since
the Vienna line tends to be a bit more laid back.
If you dont go with seperates dont spend all your money
on the amp. From my experience the pre-amp is at LEAST
as important as your amp if not more so. Again you have
many choices here.
Last but not least the Vienna's tend to be really finicky
about positioning. Spend some time on this. It took me
over two weeks to finally work it out.
Good luck