Actually, I've found that one-and-a-half pounds is the optimum amount for a 1 Gallon ziploc bag. Using any less meat, it gets too thin and you'll have a much harder time rolling it wothout splitting and then you will be much more prone to a blowout.
With 1.5 lbs evenly rolled out there is enough meat thickness to take care of just about anything you want to stuff that puppy with....plus, if fits "just right" inside that ziploc. Check out this pic- 1.5 lbs sausage and braunschweiger on top-
You can see the thickness of the sausage is good, but not too thick. Seems like that extra half pound of sausage in the ziploc doubles the thickness of the meat, strange as it sounds
You can see that whole fattie construction here-http://www.smokingmeatforums.com/for...=german+fattie
I always smoke mine until the bacon on the outside is crispy. It's always a visual thing, but every time I've temp'd it (just to know) it seems to be 160-170 F depending on what's inside. If the bacon outside is crispy then the sausage inside is always done.
This can take anywhere from 2 hours to 4 depending on how hot your smoker is running. For 250 F that should be about 2 to 2.5 hrs.
Good luck on your new addiction and let us know how it comes out. We like q-vue!