OK guys,...i'm somewhat cold natured,..50 degrees and i wear a jacket. So sometime in mid to late feb, a couple buddies want me to go camping with them at Colorado National Park. I have been told the temperatures can reach very low to possible negatives? I am looking for a lightweight sleeping bag,..price isn't to big a concern, I have been looking at the Western Mountaineering Highlite sleeping bag. What do you guys think? I definately want to stay warm and im looking for a light and comfy sleeping pad and pillow. Btw im new somewhat new to backpacking so im open to suggestions.