I had to furnish an apartment recently and I had great luck with IKEA. You can go to their warehouse and flop around on their floor units until you find one you like, and then you can have them ship one to you rolled up in a box.
Mine was heavy-ish, but not too heavy for one person to carry/drag while it was in the box. I'm sure their website shows weights if you're close to your cargo limit.
We had a Sleep Number in our last trailer and neither of us liked it very much. I'm sure they're fine at home, but ours just didn't travel very well, especially if you go up and down in altitude a lot.
