I also wouldn't exclude a single walled tent. Hammocks look attractive, but when you include under quilts, straps etc they get heavy and bulky. Bivys can be uncomfortable and many end up as heavy as a tarptent. I use a Tarptent Contrail with a custom pole that has 4 sections so it fits into my saddlebag. Total weight is 1.5lbs and it takes just 5 mins to put up. I pack the tent in a compression sack so that it takes up very little space.
+1
My Tarptent Squall 2 with Tyvek floor weighs 30 oz, versus my OR Advanced Bivy sack at 32 oz. The tent provides space to sit up and dress/undress, space to read/plan route, keep all bags/shoes/gear under rain protection, easier to answer call of nature, less heat/humidity in hot season, and potential accommodation for second person. The tent does pack larger than bivy sack, and maybe a minute more to set up / take down.
Most hammocks are no lighter than bivy sacks or some tents, and additionally require two trees/posts several feet apart.