Lots of folks like hennessy hammocks and tarptents for lightweight and packable shelters. I haven't tried either one.
I use an REI 1/4 Dome 2-man tent. Googling either term will give you more than you need to read.
For a sleeping mat, I use a Thermarest NeoAir and an Exped Air Pillow. I can put my 30 degree down bag, silk bag liner, mat and pillow into a compression sack the size of two canatloupes side by side, weighing around 3 lbs.