I deleted myself
If you're prior service you're probably familiar with these. They contain multiple bags and when used together (along with a wool hat and some good socks) are rated -30 degrees F. You can also split them apart to use in warmer weather. The outer shell is woodland camo gore-tex which is great for repelling water and remaining breathable (as long as you keep it clean). If you can find one of these on the cheap or semi-cheap it's a worthwhile purchase as you will have it for years and years and years. They can be kind of expensive for the entire system ($150ish). Highly recommended though.