Electrical Engineer- Simple Prototype-Electric Resistance heater -- Updated

Looking for electrical engineer who can design and produce simple prototype with OTS components available in the US. Project: create a self regulating radiant heat cable with rotary style thermostat/control that plugs into a GFCI wall plug. Diagram attached. Cable would be similar to a water pipe heating cable(20-60feet in length) and would have to hold stable operating temperatures of 70-140F. The radiant heat cable would be attach to some sort of simple Control/thermostat. And that would have the power cord running from it. Overall design needs to be durable and suitable for outdoor use, end use application would be in-home/commercial. Understanding of how to make it a safe product. Understanding of how to produce a prototype with OTS components that could initially support a production run of 10-20 units. Follow on work likely for right candidate. Preferably based in USA. If not based in the USA please clarify how you will source parts. Must clarify working with US based project in response for consideration.