Cure #1 is different than MTQ.
Cure 1 is used at 1 level tsp per every 5lbs of meat.
MTQ is used at 7.5 tsp per every 5 lbs and you should cut back on the salt in the recipe.
Here are some links for cure #1 and dextrose.
As far as letting it set overnight, the choice is yours. I have done both overnight and stuffing smoking right after mixing.
If you have a BassPro Shop or Gander Mountain close you can buy LEM Cure there.
Start at 130-140 for and hour or so and take 170 to finish...175 only if you need to.