Sorry, but the only 2 I would even remotly consider would be the Kestone 2920 BHWE or the Heartland Northtrail. Both of those have dry weights around 5500lbs, and you will have to be carefull how you load them. Don't know if that is before options etc. My trailer had a brochure dry weight of 3850lbs, shipped it was 4030 (cupboard door sticker number) Added 2 batteries and propane (directly on the tongue I might add) for another 200lbs, so I was almost 400lbs heavier than the brochure dry weight before I added water or any of my stuff.
These 2 will probably overload the Expy by a little, the rest will be by A LOT.
It is your Expy, your family, and only you know your level of comfort. I know I would not be happy towing one of these with our Expy. Some members on here are doing it, but usually when you ask it is just 2 or 3 people, not 6, and that makes a difference. You should try to keep the dry weight under 5500lbs, that way after options and loading you will still be ok though at the limits. There are other options, keep looking. There are lots of double and some tripple bunk configurations, maybe a couple quads.
Good luck