Speaker cables for Simaudio/ Dynaudio

I have narrowed down my search for speaker cables to two: Synergistic Research Tesla Accelerator and Nordost Heimdall. I have a Simaudio I-7 integrated and Dynaudio Confidence C1 speakers. I am currently using Signal Cable Ultra Speaker Cables which I have had for a few years. After various upgrades to speakers and electronics, speaker cables are my last upgrade.
Any thoughts on these two choices?