My wife and I have camped together for twenty years now.
For a very long time we used a "Therma-nest" sleep system that used a single synthertic 20 degree thermarest rectangular sleeping bag to cover two full sized thermarest pads which were held in by a bottom sheet with a zipper all the way around.
This was a fantastic - if heavy - sleep system. At the time I often bragged to other trad hikers about how my wife and I only used a single sleeping bag between the two of us though, and maybe it was a little lighter than two bags and two pads. It sure is comfy with the heavy pads and shared body heat!
It also got us used to the idea of using a sleeping bag as a "quilt" with just the pads below us - Long before I ever read about backpacking quilts and stuff.
That bag is about worn out now though, and has been replaced with a Ray Way 2 person kit quilt, with two layers of alpine insulation. Very warm indeed, and quite light!
For pads we now use two Thermarest regular "prolite" pads, at about a pound each.
At least in the summer. In the winter the old heavy R5 pads make a very big difference, and my wife couldn't care less about the weight...
I've slept on a walmart foam pad next to her when she was on her old thermarest pad, and before long we were both trying ( and sucseeding to a remarkable degree )to fit on top of her comfy pad!
We both use Jam 70 packs. My wife carries the quilt and both pads, our dopp kit, first aid kit, her clothing, and some snacks. She needs the big pack for that bulky quilt, and with her bad knees it is essential to keep her pack weight low.
I carry everything else - usually ( but not always ) a tent when we're together, the stove, cook kit and all the food, as well as my clothes and a tiny repair kit.
It's a good system, and our base pack weights are almost in the UL range, which is a big improvement for us.
For tents, we have a tarptent Squall 2 and the very similar Rainshadow 2.
We like single enty tents with sufficent cover to cook under in the front and a dry entrence in rainy weather.
My wifes favorite tent of all time is the bomb proof seven pound Timberline 2, but I refuse to carry that boat anchor anymore...
Edit to add -
I can't imagine not sleeping with my wife and can't imagine why any couple would want two bags - I mean I married the gal so we could sleep together every night!
It is so very very much warmer, and uh, there are other advantages as well...
I'd certainly recomend a synthetic quilt though, two bodies just produce to much moisture when snuggled under a single quilt, especially if there is any kissing going on...
But I guess that's just me. Amy likes the double down quilt I gather.