I don't know if this scenario would apply to very many people, but the control panel I built for my electric setup ended up not really being necessary. I use two 2000W 120V elements and when I built the panel my plan was to do a Brutus 20 2-Vessel recirculating mash. So for that I wanted the PID control to maintain mash temps and manual power control for the boil.
As it turns out, I found the Brutus 20 thing wasn't for me (nothing against it though). Not only that, but after some experimenting, I now just run my elements full-bore during the boil. So in the end my control panel is actually not necessary. Could've just gone with two Hot Rods w/ stainless elements and some sort of simple on/off solution. Nevertheless, I have no regrets - I really enjoyed building the panel and I learned a great deal from the process.
Cheers and enjoy the brew.