Presumably you could use an unheated and insulated HLT though, and heat the sparge water in your kettle to ~160F, then transfer to the HLT (5 gallon cooler in my case) for treatment before you start sparging and use a 1500W RIMS tube to just heat the sparge water that final step to 168F. That way you'd only need a 110V PID controlled element in the RIMS, and a manually controlled boil kettle, which could be either 240V electric, dual 110V (you could run one element while sparging with the RIMS to start heating the wort) or gas.
At the moment I brew using only a single gas heated kettle with the common two cooler HLT and MLT setup, although I've just ordered the bits for a 1500W RIMS tube, and I've already built and tested the PID controller with a 1000W bucket heater that I use to assist my stove when brewing indoors. I want to use the RIMS tube to provide the control for heating the sparge water. Since I usually fly sparge 1 pint/minute is closer to the desired flow rate.