I've heard the Grand Utopia's extensively, via a friend, that uses Purist Audio Designs cables. This system sounds amazing...so I'd definitely add Purist to your demo list...I use some Purist and mostly Transparent Audio cables is my system...but can't really comment on how they might sound with your speakers/equipment..
you have an amazing system
love your speakers and the Preamp !
do you remember what model of Purist Audio your friend using?