I'm not sure about the Tannoys DC6, from what I have read elsewhere the 6004 amp is not that powerful although rated at 45w many similar amps sound louder could be the damping, so I would look at speakers that are easy to drive like the Rega RS1s, avoid B&W 685 need plenty of power to drive them.
Looking at the sensitivity of DC6 is 86 so maybe not the best for the 6004. Can you try them out?