Dont agree with the above comment at all
I think for the OP's taste in music (and more so with regards to the B&W 684's) the C/A amp would be found lacking
Out of the list above I'd go for the Rotal RA1520 every time. However the RA06SE shouldnt be discounted either nor should the NAD C356BEE.
Would the OP look at 2nd hand amps at all; a lot more can be hand for your money going down the 2nd hand route!
The likes of (if you can find one); a Roksan K2 would be good. If not the Roksan Kandy LIII, NAD C355BEE, Arcam Alpha 10 integrated or an Arcam DiVA A85 would also fit the bill very well.
The latter Arcam amps can be had for a lot less than your budget limit so you could potentially look to add their matching power amps as well.
This would REALLY suit your speakers and tatse in music as well