I order mine from Amazon:
Beadalon Round Wire 316L Stainless Steel 22 Gauge, 10-Meter
https://www.amazon.com/dp/B001R8LLW0/ref=cm_sw_r_awd_Mcj6vb83PS6M8
If you use it in your mod, you'll have to leave it in normal "power" mode until/unless you can update your mod to work with SS in TC mode.
I don't know about op, but I picked up some plain 22g 316l beadlon wire from amazon for about 10 bucks at 32ft. Beadalon Round Wire 316L Stainless Steel 22 Gauge, 10-Meter https://www.amazon.com/dp/B001R8LLW0/ref=cm_sw_r_awd_6gdsub0YQ1X67