Hey all ULers and SULers, I need some advice about making my own down jacket.
This will be a long initial post to give enough info to receive good advice.
Now that summer is approaching, I figured I would start looking ahead to next year's gear wants. I'm trying to dial in my system for what I hope is my thru-hike of the AT in 2014. Unfortunately, due to job concerns, this could be 2015.
I'm 6'2" 175-180 pounds. I wear size large in just about every company's products I use. I live in the redwoods of Santa Cruz Mts in California and we have a pretty mild, if wet, year-round climate. However, I travel a lot and I want to take this jacket everywhere I go. I don't mind a jacket that's a little too warm, because I never hike in down anyway. I basically avoid true alpine conditions and middle of the winter snow. This will be used as a camp jacket and to augment my sleep system since I use an Enlightened Equipment Revelation 40 degree quilt.
I'm looking to create a jacket that weighs 10 ounces or less, has an adjustable hood and waist, has 4-5 ounces of fill, and uses 800-900 fp. A full zipper is nice, but not necessary. It could be a quarter to half zipper like the Nunatak Skaha, or use a few buttons like my Stoic does. Hand pockets are unnecessary, since I never use them. For a shell color, I prefer black, dark gray, or dark green, nothing flashy. I don't care about the liner color. I'm still undecided about sewn-through or baffled construction.
I've seen the Whitney kit on the thru-hiker website and that seems like a good starting point. Are there other kits out there closer to what I'm looking for? Has somebody else already created a similar jacket?
My brother works in the fashion industry in SF, and has numerous contacts in the sewing world. I'm hoping to use their experience when putting this jacket together.
Last but not least, if I can't find a finished kit, I'm wondering where I source the material such as Pertex Quantum, or M50, or 800-900 fp down? What is the best all-around shell material?
Thanks for any advice and helpful links. I appreciate you taking the time to read this post and offer insights.

