This setup could work for you with minimal cost. It uses a single PID and temp probe. The temp probe is placed and remains in the HLT. Use one pump to recirculate the HLT water to prevent stratification within it. Use your copper coil as the heat exchanger and then the second pump to recirculate the mash through it. This will maintain the mash temp throughout.
After transfer to the BOIL kettle, the PID gets used in manual mode to control the boil rate.
As usual - click on the image to see a full size diagram that is printable on Tabloid paper (11" x 17")
Hope this helps you.