I'm similar to you in regards to my set-ups. Gatewood & bivy on the ground and hammock in the trees.
My JRB No Sniveller has seen me thru many nights in those temps in both shelters. Mike & Tim both make great choices, based on owner feedback (I bought a tarp from Mike and it is a great piece of gear). I feel confident MLD makes a great quilt, too.
Seeing one in person, as you've planned, is a great idea.
Aside from the high quality of JRB gear, based on my experience, extending the range down into the high teens can be easily done w/ a down hood/balaclava and a puffy jacket. The bivy greatly helps this, as well.
***Edit: I realized after the fact that I misunderstood: you're looking for one, rather than opinions. Hope my advice helps as you evaluate options. Sorry about that!