I run AC Delco glow plugs and have for almost 10 years no issues. I also change to 5W-40 in the winter, I use rotella T synth.
I would stay away form the magnetic heaters and just install the regular in block one. The mag ones tend to fall off if you don't remove them before you drive and they get less effective as the block gets dirty or oily. They also hang down a good amount and get knocked off by road ice and snow. Been there done that.
Also ref the generator, to be honest it is not required and will be a waste of money imho. For the amount that it may be useful to you its not worth the money, it would be way more cost effective to get a high idle kit installed and just not turn off you truck if you are worried about it.
Like I said before my truck spends months at -20F to -35F just sitting in my driveway and all I use is an oil pan heater and block heater. If you are really set on a way to help starting in a place without power go for, like Ozrockrat said, a remote start with temp sensor to start your truck when it gets to a certian temp. Or if you want to get a generator type solution go for an espar fuel fired coolant heater. It runs off of the diesel in the tank to heat the coolant when the engine is not running. They use about 1/4 to 1/2 of a pop can of diesel an hour. They are popular up here.
http://espar.com/html/products/hydronic4.html
http://www.polarmobility.com/fuel+fired+coolant+heaters.html
It just does not get cold enough for long enough in WI to need a generator setup. They don't even do that in the arctic, it is cheap to just not turn the truck off. According to the inter webs the lowest average temp in you area is around the 7 to 10F, I don't even plug in my truck until it gets to about 10F and my oil pan heater doesn't get plugged in until it gets to about 5 to 0F . I think you are over thinking this. Like I said at the most for your area I think you will need a block heater and maybe an oil pan heater.
Shawn