Hello! I've been looking to get a deal on a quality down 20-degree-or-so sleeping bag for a while now, and I have the opportunity to get a new Western Mountaineering Ultralite bag for $275-300. Thing is, I am just over 5'8" (about 150 lbs) and the only bags that are available are the 5'6" one and the 6'6" one.
How do the WM bags run? Unfortunately, I don't have the opportunity to "try on" a WM bag, so I'll have to rely on your expertise. Should I hold out for a 6' bag, or should I jump on this deal? If so, do you think I would have trouble fitting into the 5'6" bag? The weight difference is negligible, so I wouldn't mind going for the 6'6" bag, but would that compromise the 20 degree rating significantly? I am relatively new to backpacking, but plan on doing a significant portion of the Pacific Crest Trail this summer and want to invest in a quality bag, but I can't really justify spending more than $300 on a bag :).
Thanks in advance for any and all help!

