I own 7 mattresses/pads and I will discuss the three with the highest comfort to weight ratio.
Montbell inflatable, short (120cm), 340grams
Montbell inflatable, long(180cm), 370grams
Montbell UL foam mattress, 120cm, 360grams
My Prolite3 and Coleman are too heavy and my GG Torsolite is too uncomfortable for me.
The MB inflatables are a full 5cm thick, with 6 independent chambers. Keep the two edge chambers a little more full and it will create a butter-dish type shape which is very comfortable, even sleeping on concrete or rocks; both of which I have done with this mat. Put something under your feet if you choose the 120cm version. I use the Montbell pillow (80grams) which has a notch in the middle to cradle your head, and I plan to toggle it to the mat.
The UL foam mattress has 90cm, 120, 150, 180, 180camp versions and uses solid (not die cut) foam with a high R value. Last winter I slept on ice with this and a 1/8" Gossamer Gear Thinlight in my tent. Could not feel any heat loss. The air mattresses would have been very cold in that situation.
As for weight limits I don't know, but the two inflatables are very strong fabric. Ive had two people totaling 120kg sitting on them. The UL mattress is maybe less strong..
If this is for the 6 warmest months Id get the 120cm inflatable for its luxury. 6 coldest months the UL foam pad and a Thinlight.
If Montbell CO won't order it from Japan for you, Ill ship you one. I've bought many MB items for BPL members.