I would use an ale yeast instead of the bread, since you want it sweet. However, running your recipe through a brewing calculator, I'm getting a good 18% potential ABV (1.142 SG)--i.e. a standard wine yeast would leave you some residual sweetness (as long as you don't go with 1116/1118). If you want it lower abv than that, I say omit the brown sugar, and use maybe 1/4 cup molasses in it's place (for the flavour) (which should bring it down to around 15% potential ABV).
If it were me, I would use fresh pumpkin (and roast it), bring it up to a full three pounds, and boil it to extract the flavours...that way there is less solids in the must. If you carve a jack-o-lantern you can get all you need from scraping the insides...
Spices: If you aren't concerned about particulate matter (since you are planning on ground nutmeg), I say to use full on pumpkin pie spice. Otherwise, I don't have much to say, other than that will probably be too much cinnamon--try 1 stick, and add more in secondary if you want.
Hope that helps, and happy brewing.
There is one secret ingredient that makes anything better......time.
Primary: House Cider; Rhubarb Wine, Carrot Wine
Secondary: Rhubarb Wine
Tertiary (or higher):
Drinking: House Cider, Cherry Cyser, Belgian Walnut Graff