I've got the Raven xl bivy on order from TiGoat. At $110 (before upgrades), it's definitely got bang for the buck.
It sounds like you're going need to focus on girth dimensions. How tall are you? I believe the Raven is focused on adding length for the taller folk. I talked to Doug at TiGoat and he did say the Ptarmigan and Raven have the same shoulder and foot girth dimensions, so you might want to check out their site and give him a call with your measurements and see what he says.
As far as weight, Doug said the Raven is a bit over 7 ounces with the optional full net hood (I have not confirmed this on my scale as yet though).