There are at least a couple of Tannoy dealers who frequent this forum...perhaps they could add any sage advice of theirs?
Remember you can mix and match...Rev Sig DCT6s at the front, DC4s at the back. The sound will still be a good fit. The Rev Sig DC4s are punchy little things with bags of detail. Love them to bits. Or one bit really, they're also an absolutely solid chunk of wood.
I also didn't particularly like the Tannoy sub at the time, and some of their new ones out don't get such brilliant reviews as the rest of the speakers. For me, a lot was to do with it being down firing and me worrying about my downstairs neighbour. Whether it actually makes any difference if it's down or front firing is debatable, but I felt bad about it so looked for an alternative. You might want to look at a sub as a separate venture. There are a couple of Rev Sig owners here who use Sunfire or Velodyne subs. Mine is a Velodyne MicroVee
Toshiba 42WLT66, Yamaha RX-V3900, Panasonic DMP-BD55, Sony HDX870, Tannoy Rev Sig DC4T, DC4, DC4LCR, Velodyne MicroVee, Tacima CS929, Apollo AZ Stands, QED/Chord HDMI cables, Chord Cobra 3 Sub Cable, Cheap Speaker cable, Grado SR80 Headphones