Great discussion!
Here are a couple of random thoughts on some of the topics that have been touched on.
Rytek Kutas who wrote THE definitive book on sausage making says that 160 is the optimum temperature for smoking sausage. Since sausage is usually no more than an inch to an inch a 1/2 think this temp works well.
For thicker cuts of meat, it take a LONG time to get to the target of 160 internal temp.
For lower temperatures, you should use a nitrate curing agent to kill the pathogens. Kutas' book has a really good section on cures and how to use them and how they work.
I designed and built an electric fired smoker for my sausage smoking. I had a thermostat on it so I could set any temperature I wanted. The wattage of your heating element needs to be balanced with the volume of your smoker to be able to maintain the temperatures you are looking for. If you want to do cold smoking or otherwise use a lower temperature, a lower wattage element is sufficient. If you want to go up to 275 ot 300 degrees, you need a higher wattage element.
One issue you run into with a homemade electric smoker, is getting the element hot enough to cause the wood chips to smoke.
An electric charcoal starter makes a good, inexpensive element. sausagemaker.com has a good temperature controlller for about $150.
With the smoker I made, I could smoke four 14 pound turkeys at the same time.
Now, with all that said, there is no substitute for charcoal fired smoking for flavor. My electroc fired smoker was good, but the flavor could not match the flavor of charcoal!
There are some great ideas in this discussion! Thanks!!
Mike