I just acquired 3 kegs with one already having the top cut to work as a kettle. The other two will need to have the tops cut likewise.. that part I DO understand.

I'd like to setup a HERMS system. I have access to controllers and temperature sensors and such, but the equipment and placement of the equipment is what is confusing me. I don't want to drill into those keg/kettles in the wrong places or too often etc..
I use propane as my heat source.. and have only the one burner. I was thinking that I could heat the HLT to near Strike temperature via propane, then switch to a 110v heating element to reach final strike temp... then do the same to maintain mash temp? I could monitor the temp of the wort as it re-enters the mash tun from the heat exchanger in the HLT... in this way I could do a continuous recirculation.
Seems pretty straight forward? Is there something I'm missing?
I guess what I'd need to do then is.
1) put a bulkhead into the MLT at the bottom, connected to the false bottoms pickup tube.
2) connect the MLT to a pump and the pump to a bulkhead on the HLT
3) connect the heat exchanger (wort chiller) to the internal bulkhead fittings
4) connect HLT back to top of MLT and monitor temperature of returned wort
If wort returned temp is too low, then turn on electric heating element until the correct temperature is reached...
If this sounds reasonable, can anybody suggest a way to install an electric heating element into the HLT? Should I punch it into the HLT or is there a better way to install it?
Thank you!!!