i also agree that the red dawns (and blue heavens) are a bit harsh on treble (as interconnects, that is).
i have vdh firsts, seconds, "the bay"s, orchids, and digicouplers (some of which i do use as analog interconnects) and i would say that they are all definitely more pleasant on treble in my system than the red dawns were. the orchids are the most extended, the bays are fantastic bang for buck (or, in your case bang for pound or euro), and the firsts and seconds do amazing things for soundstage. i've never tried their speaker cables.
another cable you could try would be the analysis plus solo crystal, they do everything well, both interconnect and speaker.
and mit cables are the definition of "anti harshness" and indeed, my shotgun ma cables are my favorite interconnects i've ever heard (short of the mit oracles at a mind numbing price). even the least expensive non-networked cables sound really good and are very smooth.
i would always qualify my recommendations with a "try before you buy" addendum, though, as i'm sure some cables could sound totally different in other systems, and i've never owned components from the brands you mention....
and is it safe to assume you'll be taking in the action at murrayfield this weekend?