If you’re looking for a cheap but perfect hotwire setup, you could go down the road I did…
I bought an electronic kitset from the local electronics store, and soldered it up myself.
It’ll run 20A at 24V.
But I just connect it to my cars 12v battery, and twiddle the dial up and down to change the heat.
Perfect fingertip control, and more power than I need.
It was called a “Motor speed controller”, so it’s the same thing as the model train transformers, but heaps more powerful.
Get something that you can vary the power on by turning a dial/knob, you won’t regret it!
Kit