Should I upgrade my speaker cables?

I got 4 Classe 25s that are bridged and pumping out 4000 watts to my Bower 802D3s , im bi amping and running 1000 to the highs and 1000 to the lows of each speaker, got 2 sets of Nordost Heimdell 2 speaker cables, which have 18 lines of 22 awg solid core copper. I feel that might be to thin to be running 1000 watts and considering selling the Heimdell 2s and upgrading to something with thicker gauges, am I fine with the Heimdells or should I upgrade now that I’m running 1000 watt’s per cable? What is recommended? My budget is $5k-$8k per set, I need 2 sets