There are several good sleeping bag companies, try taking a peek in a Gander Mountain or similar catalog and you should ge ta good idea of what is out there. I use mainly wool blankets, in cold weather they are folded across each other back and forth to make an envelope with the foot folded under the previous layer.
In cold weather a mummy type bag is the best usually. Keeoping your head covered is most essential to staying warm. For added, Ummm interest, two bags can be zipped together to accomdate you choice of sleeping companion.