My 1986 31' Sovereign
weighs in at about 7800# with an average amount of stuff in it. Tows like a dream and has lots of closet space and decent tankage (both considerations for full-timing.
It is placarded for a gross weight of 8600# but I can't imagine how you would get it that heavy unless you collected floor safes or dumbells. I tow it with a Nissan Titan with a 9500# tow rating with no problems (some 25000+ miles so far).
Does it look pristine? No. Does it look pretty darn good? You betcha. All told I have about $20k in it but everything is new/refurbished and it is (knock on wood) solid as a rock.
31 footers of all ages are generally the most common models. I know it sounds like too much trailer but after traveling in it 12 of the past 24 months, I can't imagine doing it in anything much smaller.
Good Luck on your quest. Be patient and you'll find your Airstream.