Here are the answers to your questions in the PM and your post. If I missed anything or you have any other questions, let me know.
The honeywell valve is the Y8610U retrofit kit. It includes the valve, wiring harness/controller and igniter assembly. You will need to buy a honeywell pilot burner separately. The kit is being phased out in favor of a newer model, so I got a pretty decent price on it. It works perfectly. Since it uses a 1/2" threaded input and output, it worked perfecty with the 1/2" iron pipe we used for the plumbing.
There are two regulators in the stand, since I used both high pressure and low pressure burners. From the tank, there is a high pressure regulator and host going to the stand. I used a 15 psi Bayou Classic regulator assembly. Before the honeywell valve, I needed another regulator to convert the high pressure to low pressure. I used the More Beer low pressure regulator
. We just took out the brass fittings and plumbed it into the pipe. You can probably find one cheaper elsewhere, but I knew this one would work, so I went with it.
The burner on the mash tun makes life much easier. I can heat the strike water and dough in and then use the recirculation to maintain the temp and/or raise the temp for mashout or step mashes. It would take forever
to get room temperature water to 150 degrees + with just the recirculation. I don't use the burner under the mash tun after the grain has been added to the strike water, just to avoid any risk or burned wort. Some people do it and don't have issues, but I wanted to avoid it. One less thing to worry about...