I have tried using hammocks several times and never enjoyed the experience. Furthermore, I am near or above tree line which makes hammocks useless. I would suggest you check out people who love hammocks such as Sgt Rock’s Hammocks 101.
In warm weather nothing will keep you as cool as a nice hammock. In moderate weather many people find the aluminized windshield shades work well. In cooler weather you will need more insulation. My limited experience is that insulation which is adequate for when I was on the ground down to around 30F kept me almost warm enough at 48F in a hammock. The Gossamer Gear Thinlight Pad (1/4 or 3/8″) looks like a good under insulation layer for cool-moderate weather. I won’t recommend the 1/8″ Thinlight because it’s too easy to hole and isn’t stiff enough to stay in place. In colder weather I would encourage considering using an under quilt. There are a variety of companies that make under-quilts.