4425, You have Niagra 7000 which is great and your amp is one of the best. As you know, the cord to connect the power conditioner to the wall ac is very important for your hi level equipment. to get the best sound possible.
I have denali 6000T, and I tired Alpha HC, Alpha NR on it but until I got the Sigma HC I did not hear full potential of my denali and gear connected to it (gryphon diablo 300). Try to find a used sigma HC or new NR for a great price you will not regret it. You can pm me for a great shunyata dealer that is also AQ dealer.